| Group
Guide to the Secure Configuration of Debian 13
Group contains 19 groups and 46 rules |
| Group
System Settings
Group contains 18 groups and 46 rules |
[ref]
Contains rules that check correct system settings. |
| Group
Installing and Maintaining Software
Group contains 2 groups and 3 rules |
[ref]
The following sections contain information on
security-relevant choices during the initial operating system
installation process and the setup of software
updates. |
| Group
System and Software Integrity
Group contains 1 rule |
[ref]
System and software integrity can be gained by installing antivirus, increasing
system encryption strength with FIPS, verifying installed software, enabling SELinux,
installing an Intrusion Prevention System, etc. However, installing or enabling integrity
checking tools cannot prevent intrusions, but they can detect that an intrusion
may have occurred. Requirements for integrity checking may be highly dependent on
the environment in which the system will be used. Snapshot-based approaches such
as AIDE may induce considerable overhead in the presence of frequent software updates. |
Rule
Disable Prelinking
[ref] | The prelinking feature changes binaries in an attempt to decrease their startup
time. In order to disable it, change or add the following line inside the file
/etc/sysconfig/prelink:
PRELINKING=no
Next, run the following command to return binaries to a normal, non-prelinked state:
$ sudo /usr/sbin/prelink -ua
| | Rationale: | Because the prelinking feature changes binaries, it can interfere with the
operation of certain software and/or modes such as AIDE, FIPS, etc. | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_disable_prelink | | References: | | cis-csc | 11, 13, 14, 2, 3, 9 | | cjis | 5.10.1.3 | | cobit5 | APO01.06, BAI02.01, BAI03.05, BAI06.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS04.07, DSS05.03, DSS06.02, DSS06.06 | | cui | 3.13.11 | | isa-62443-2009 | 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.4 | | isa-62443-2013 | SR 3.1, SR 3.3, SR 3.4, SR 3.8, SR 4.1, SR 7.6 | | iso27001-2013 | A.11.2.4, A.12.1.2, A.12.2.1, A.12.5.1, A.12.6.2, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.8.2.3 | | nerc-cip | CIP-003-8 R4.2, CIP-007-3 R5.1 | | nist | SC-13, CM-6(a) | | nist-csf | PR.DS-1, PR.DS-6, PR.DS-8, PR.IP-1 | | pcidss | Req-11.5 | | cis | 1.5.6 |
| |
|
| Group
Disk Partitioning
Group contains 2 rules |
[ref]
To ensure separation and protection of data, there
are top-level system directories which should be placed on their
own physical partition or logical volume. The installer's default
partitioning scheme creates separate logical volumes for
/, /boot, and swap.
- If starting with any of the default layouts, check the box to
\"Review and modify partitioning.\" This allows for the easy creation
of additional logical volumes inside the volume group already
created, though it may require making
/'s logical volume smaller to
create space. In general, using logical volumes is preferable to
using partitions because they can be more easily adjusted
later. - If creating a custom layout, create the partitions mentioned in
the previous paragraph (which the installer will require anyway),
as well as separate ones described in the following sections.
If a system has already been installed, and the default
partitioning
scheme was used, it is possible but nontrivial to
modify it to create separate logical volumes for the directories
listed above. The Logical Volume Manager (LVM) makes this possible. |
Rule
Ensure /dev/shm is configured
[ref] | The /dev/shm is a traditional shared memory concept.
One program will create a memory portion, which other processes
(if permitted) can access. If /dev/shm is not configured,
tmpfs will be mounted to /dev/shm by systemd. Warning:
This rule does not have a remediation.
It is expected that this will be managed by systemd and will be a tmpfs partition. | | Rationale: | Any user can upload and execute files inside the /dev/shm similar to
the /tmp partition. Configuring /dev/shm allows an administrator
to set the noexec option on the mount, making /dev/shm useless for an attacker to
install executable code. It would also prevent an attacker from establishing a
hardlink to a system setuid program and wait for it to be updated. Once the program
was updated, the hardlink would be broken and the attacker would have his own copy
of the program. If the program happened to have a security vulnerability, the attacker
could continue to exploit the known flaw. | | Severity: | low | | Rule ID: | xccdf_org.ssgproject.content_rule_partition_for_dev_shm | | References: | | |
|
Rule
Ensure /tmp Located On Separate Partition
[ref] | The /tmp directory is a world-writable directory used
for temporary file storage. Ensure it has its own partition or
logical volume at installation time, or migrate it using LVM. | | Rationale: | The /tmp partition is used as temporary storage by many programs.
Placing /tmp in its own partition enables the setting of more
restrictive mount options, which can help protect programs which use it. | | Severity: | low | | Rule ID: | xccdf_org.ssgproject.content_rule_partition_for_tmp | | References: | | cis-csc | 12, 15, 8 | | cobit5 | APO13.01, DSS05.02 | | isa-62443-2013 | SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6 | | iso27001-2013 | A.13.1.1, A.13.2.1, A.14.1.3 | | nist | CM-6(a), SC-5(2) | | nist-csf | PR.PT-4 | | os-srg | SRG-OS-000480-GPOS-00227 | | cis | 1.1.2.1.1 |
| |
|
| Group
Account and Access Control
Group contains 1 group and 1 rule |
[ref]
In traditional Unix security, if an attacker gains
shell access to a certain login account, they can perform any action
or access any file to which that account has access. Therefore,
making it more difficult for unauthorized people to gain shell
access to accounts, particularly to privileged accounts, is a
necessary part of securing a system. This section introduces
mechanisms for restricting access to accounts under
Debian 13. |
| Group
Warning Banners for System Accesses
Group contains 1 rule |
[ref]
Each system should expose as little information about
itself as possible.
System banners, which are typically displayed just before a
login prompt, give out information about the service or the host's
operating system. This might include the distribution name and the
system kernel version, and the particular version of a network
service. This information can assist intruders in gaining access to
the system as it can reveal whether the system is running
vulnerable software. Most network services can be configured to
limit what information is displayed.
Many organizations implement security policies that require a
system banner provide notice of the system's ownership, provide
warning to unauthorized users, and remind authorized users of their
consent to monitoring. |
Rule
Ensure Message Of The Day Is Configured Properly
[ref] | To configure the system message of the day banner edit the /etc/motd file.
Replace the default text with a message compliant with the local site policy.
The message should not contain information about operating system version,
release, kernel version or patch level.
The recommended banner text can be tailored in the XCCDF Value xccdf_org.ssgproject.content_value_cis_banner_text:
Authorized users only. All activity may be monitored and reported.
| | Rationale: | Warning messages inform users who are attempting to login to the system of their legal
status regarding the system and must include the name of the organization that owns
the system and any monitoring policies that are in place. Displaying OS and patch level
information in login banners also has the side effect of providing detailed system
information to attackers attempting to target specific exploits of a system. Authorized
users can easily get this information by running the uname -a command once they
have logged in. | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_banner_etc_motd_cis | | References: | | |
|
| Group
AppArmor
Group contains 3 rules |
[ref]
Many security vulnerabilities result from bugs in trusted programs. A trusted
program runs with privileges that attackers want to possess. The program fails
to keep that trust if there is a bug in the program that allows the attacker to
acquire said privilege.
AppArmor® is an application security solution designed specifically to apply
privilege confinement to suspect programs. AppArmor allows the administrator to
specify the domain of activities the program can perform by developing a
security profile. A security profile is a listing of files that the program may
access and the operations the program may perform. AppArmor secures
applications by enforcing good application behavior without relying on attack
signatures, so it can prevent attacks even if previously unknown
vulnerabilities are being exploited. |
Rule
Ensure AppArmor Utils is installed
[ref] | AppArmor provide Mandatory Access Controls. | | Rationale: | Without a Mandatory Access Control system installed only the default
Discretionary Access Control system will be available. | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_package_apparmor-utils_installed | | References: | | |
|
Rule
Ensure AppArmor is installed
[ref] | AppArmor provide Mandatory Access Controls. | | Rationale: | Without a Mandatory Access Control system installed only the default
Discretionary Access Control system will be available. | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_package_apparmor_installed | | References: | | os-srg | SRG-OS-000368-GPOS-00154, SRG-OS-000312-GPOS-00122, SRG-OS-000312-GPOS-00123, SRG-OS-000312-GPOS-00124, SRG-OS-000324-GPOS-00125, SRG-OS-000370-GPOS-00155 | | anssi | R45 | | cis | 1.3.1.1 |
| |
|
Rule
Ensure AppArmor is enabled in the bootloader configuration
[ref] | Configure AppArmor to be enabled at boot time and verify that it has not been
overwritten by the bootloader boot parameters.
Note: This recommendation is designed around the grub bootloader, if LILO or
another bootloader is in use in your environment, enact equivalent settings. | | Rationale: | AppArmor must be enabled at boot time in your bootloader configuration to
ensure that the controls it provides are not overridden. | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_grub2_enable_apparmor | | References: | | |
|
| Group
GRUB2 bootloader configuration
Group contains 2 groups and 4 rules |
[ref]
During the boot process, the boot loader is
responsible for starting the execution of the kernel and passing
options to it. The boot loader allows for the selection of
different kernels - possibly on different partitions or media.
The default Debian 13 boot loader for x86 systems is called GRUB2.
Options it can pass to the kernel include single-user mode, which
provides root access without any authentication, and the ability to
disable SELinux. To prevent local users from modifying the boot
parameters and endangering security, protect the boot loader configuration
with a password and ensure its configuration file's permissions
are set properly. |
| Group
Non-UEFI GRUB2 bootloader configuration
Group contains 3 rules |
[ref]
Non-UEFI GRUB2 bootloader configuration |
Rule
Verify /boot/grub/grub.cfg User Ownership
[ref] | The file /boot/grub/grub.cfg should
be owned by the root user to prevent destruction
or modification of the file.
To properly set the owner of /boot/grub/grub.cfg, run the command:
$ sudo chown root /boot/grub/grub.cfg
| | Rationale: | Only root should be able to modify important boot parameters. | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_file_owner_grub2_cfg | | References: | | cis-csc | 12, 13, 14, 15, 16, 18, 3, 5 | | cjis | 5.5.2.2 | | cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02 | | cui | 3.4.5 | | hipaa | 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii) | | isa-62443-2009 | 4.3.3.7.3 | | isa-62443-2013 | SR 2.1, SR 5.2 | | iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5 | | nist | CM-6(a), AC-6(1) | | nist-csf | PR.AC-4, PR.DS-5 | | pcidss | Req-7.1 | | os-srg | SRG-OS-000480-GPOS-00227 | | anssi | R29 | | cis | 1.4.2 | | pcidss4 | 2.2.6, 2.2 |
| |
|
Rule
Verify /boot/grub/grub.cfg Permissions
[ref] | File permissions for /boot/grub/grub.cfg should be set to 600.
To properly set the permissions of /boot/grub/grub.cfg, run the command:
$ sudo chmod 600 /boot/grub/grub.cfg
| | Rationale: | Proper permissions ensure that only the root user can modify important boot
parameters. | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_file_permissions_grub2_cfg | | References: | | cis-csc | 12, 13, 14, 15, 16, 18, 3, 5 | | cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02 | | cui | 3.4.5 | | hipaa | 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii) | | isa-62443-2009 | 4.3.3.7.3 | | isa-62443-2013 | SR 2.1, SR 5.2 | | iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5 | | nist | CM-6(a), AC-6(1) | | nist-csf | PR.AC-4, PR.DS-5 | | anssi | R29 | | cis | 1.4.2 | | pcidss4 | 2.2.6, 2.2 |
| |
|
Rule
Set Boot Loader Password in grub2
[ref] | The grub2 boot loader should have a superuser account and password
protection enabled to protect boot-time settings.
Since plaintext passwords are a security risk, generate a hash for the password
by running the following command:
# grub2-setpassword
When prompted, enter the password that was selected.
Warning:
To prevent hard-coded passwords, automatic remediation of this control is not available. Remediation
must be automated as a component of machine provisioning, or followed manually as outlined above.
Also, do NOT manually add the superuser account and password to the
grub.cfg file as the grub2-mkconfig command overwrites this file. | | Rationale: | Password protection on the boot loader configuration ensures
users with physical access cannot trivially alter
important bootloader settings. These include which kernel to use,
and whether to enter single-user mode. | | Severity: | high | | Rule ID: | xccdf_org.ssgproject.content_rule_grub2_password | | References: | | cis-csc | 1, 11, 12, 14, 15, 16, 18, 3, 5 | | cobit5 | DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.06, DSS06.10 | | cui | 3.4.5 | | hipaa | 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii) | | isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4 | | isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7 | | iso27001-2013 | A.18.1.4, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5 | | nist | CM-6(a) | | nist-csf | PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.PT-3 | | ospp | FIA_UAU.1 | | os-srg | SRG-OS-000080-GPOS-00048 | | anssi | R5 | | cis | 1.4.1 |
| |
|
| Group
UEFI GRUB2 bootloader configuration
Group contains 1 rule |
[ref]
UEFI GRUB2 bootloader configuration Warning:
UEFI generally uses vfat file systems, which does not support Unix-style permissions
managed by chmod command. In this case, in order to change file permissions for files
within /boot/efi it is necessary to update the mount options in /etc/fstab file and
reboot the system. |
Rule
Set the UEFI Boot Loader Password
[ref] | The grub2 boot loader should have a superuser account and password
protection enabled to protect boot-time settings.
Since plaintext passwords are a security risk, generate a hash for the password
by running the following command:
# grub2-setpassword
When prompted, enter the password that was selected.
Warning:
To prevent hard-coded passwords, automatic remediation of this control is not available. Remediation
must be automated as a component of machine provisioning, or followed manually as outlined above.
Also, do NOT manually add the superuser account and password to the
grub.cfg file as the grub2-mkconfig command overwrites this file. | | Rationale: | Password protection on the boot loader configuration ensures
users with physical access cannot trivially alter
important bootloader settings. These include which kernel to use,
and whether to enter single-user mode. | | Severity: | high | | Rule ID: | xccdf_org.ssgproject.content_rule_grub2_uefi_password | | References: | | cis-csc | 11, 12, 14, 15, 16, 18, 3, 5 | | cobit5 | DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.03, DSS06.06 | | cui | 3.4.5 | | hipaa | 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii) | | isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4 | | isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7 | | iso27001-2013 | A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5 | | nist | CM-6(a) | | nist-csf | PR.AC-4, PR.AC-6, PR.PT-3 | | ospp | FIA_UAU.1 | | os-srg | SRG-OS-000080-GPOS-00048 | | anssi | R5 | | cis | 1.4.1 |
| |
|
| Group
Network Configuration and Firewalls
Group contains 1 group and 1 rule |
[ref]
Most systems must be connected to a network of some
sort, and this brings with it the substantial risk of network
attack. This section discusses the security impact of decisions
about networking which must be made when configuring a system.
This section also discusses firewalls, network access
controls, and other network security frameworks, which allow
system-level rules to be written that can limit an attackers' ability
to connect to your system. These rules can specify that network
traffic should be allowed or denied from certain IP addresses,
hosts, and networks. The rules can also specify which of the
system's network services are available to particular hosts or
networks. |
| Group
Uncommon Network Protocols
Group contains 1 rule |
[ref]
The system includes support for several network protocols which are not commonly used.
Although security vulnerabilities in kernel networking code are not frequently discovered,
the consequences can be dramatic. Ensuring uncommon network protocols are disabled
reduces the system's risk to attacks targeted at its implementation of those protocols. Warning:
Although these protocols are not commonly used, avoid disruption
in your network environment by ensuring they are not needed
prior to disabling them. |
Rule
Disable IEEE 1394 (FireWire) Support
[ref] | The IEEE 1394 (FireWire) is a serial bus standard for
high-speed real-time communication.
To configure the system to prevent the firewire-core
kernel module from being loaded, add the following line to the file /etc/modprobe.d/firewire-core.conf:
install firewire-core /bin/false
This entry will cause a non-zero return value during a firewire-core module installation
and additionally convey the meaning of the entry to the user in form of an error message.
If you would like to omit a non-zero return value and an error message, you may want to add a different line instead
(both /bin/true and /bin/false are allowed by OVAL and will be accepted by the scan):
install firewire-core /bin/true
| | Rationale: | Disabling FireWire protects the system against exploitation of any
flaws in its implementation. | | Severity: | low | | Rule ID: | xccdf_org.ssgproject.content_rule_kernel_module_firewire-core_disabled | | References: | | |
|
| Group
File Permissions and Masks
Group contains 6 groups and 34 rules |
[ref]
Traditional Unix security relies heavily on file and
directory permissions to prevent unauthorized users from reading or
modifying files to which they should not have access.
Several of the commands in this section search filesystems
for files or directories with certain characteristics, and are
intended to be run on every local partition on a given system.
When the variable PART appears in one of the commands below,
it means that the command is intended to be run repeatedly, with the
name of each local partition substituted for PART in turn.
The following command prints a list of all xfs partitions on the local
system, which is the default filesystem for Debian 13
installations:
$ mount -t xfs | awk '{print $3}'
For any systems that use a different
local filesystem type, modify this command as appropriate. |
| Group
Verify Permissions on Important Files and
Directories
Group contains 1 rule |
[ref]
Permissions for many files on a system must be set
restrictively to ensure sensitive information is properly protected.
This section discusses important
permission restrictions which can be verified
to ensure that no harmful discrepancies have
arisen. |
Rule
Enable Kernel Parameter to Enforce DAC on Hardlinks
[ref] | To set the runtime status of the fs.protected_hardlinks kernel parameter, run the following command: $ sudo sysctl -w fs.protected_hardlinks=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: fs.protected_hardlinks = 1
| | Rationale: | By enabling this kernel parameter, users can no longer create soft or hard links to
files which they do not own. Disallowing such hardlinks mitigate vulnerabilities
based on insecure file system accessed by privileged programs, avoiding an
exploitation vector exploiting unsafe use of open() or creat(). | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_sysctl_fs_protected_hardlinks | | References: | | nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2 | | nist | CM-6(a), AC-6(1) | | os-srg | SRG-OS-000312-GPOS-00122, SRG-OS-000312-GPOS-00123, SRG-OS-000324-GPOS-00125 | | anssi | R14 | | cis | 1.5.1 |
| |
|
| Group
Restrict Dynamic Mounting and Unmounting of
Filesystems
Group contains 6 rules |
[ref]
Linux includes a number of facilities for the automated addition
and removal of filesystems on a running system. These facilities may be
necessary in many environments, but this capability also carries some risk -- whether direct
risk from allowing users to introduce arbitrary filesystems,
or risk that software flaws in the automated mount facility itself could
allow an attacker to compromise the system.
This command can be used to list the types of filesystems that are
available to the currently executing kernel:
$ find /lib/modules/`uname -r`/kernel/fs -type f -name '*.ko'
If these filesystems are not required then they can be explicitly disabled
in a configuratio file in /etc/modprobe.d. |
Rule
Disable Mounting of cramfs
[ref] |
To configure the system to prevent the cramfs
kernel module from being loaded, add the following line to the file /etc/modprobe.d/cramfs.conf:
install cramfs /bin/false
This entry will cause a non-zero return value during a cramfs module installation
and additionally convey the meaning of the entry to the user in form of an error message.
If you would like to omit a non-zero return value and an error message, you may want to add a different line instead
(both /bin/true and /bin/false are allowed by OVAL and will be accepted by the scan):
install cramfs /bin/true
This effectively prevents usage of this uncommon filesystem.
The cramfs filesystem type is a compressed read-only
Linux filesystem embedded in small footprint systems. A
cramfs image can be used without having to first
decompress the image. | | Rationale: | Removing support for unneeded filesystem types reduces the local attack surface
of the server. | | Severity: | low | | Rule ID: | xccdf_org.ssgproject.content_rule_kernel_module_cramfs_disabled | | References: | | cis-csc | 11, 14, 3, 9 | | cobit5 | BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06 | | cui | 3.4.6 | | isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3 | | isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6 | | iso27001-2013 | A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2 | | nist | CM-7(a), CM-7(b), CM-6(a) | | nist-csf | PR.IP-1, PR.PT-3 | | os-srg | SRG-OS-000095-GPOS-00049 | | cis | 1.1.1.1 |
| |
|
Rule
Disable Mounting of freevxfs
[ref] |
To configure the system to prevent the freevxfs
kernel module from being loaded, add the following line to the file /etc/modprobe.d/freevxfs.conf:
install freevxfs /bin/false
This entry will cause a non-zero return value during a freevxfs module installation
and additionally convey the meaning of the entry to the user in form of an error message.
If you would like to omit a non-zero return value and an error message, you may want to add a different line instead
(both /bin/true and /bin/false are allowed by OVAL and will be accepted by the scan):
install freevxfs /bin/true
This effectively prevents usage of this uncommon filesystem. | | Rationale: | Linux kernel modules which implement filesystems that are not needed by the
local system should be disabled. | | Severity: | low | | Rule ID: | xccdf_org.ssgproject.content_rule_kernel_module_freevxfs_disabled | | References: | | cis-csc | 11, 14, 3, 9 | | cobit5 | BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06 | | cui | 3.4.6 | | isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3 | | isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6 | | iso27001-2013 | A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2 | | nist | CM-7(a), CM-7(b), CM-6(a) | | nist-csf | PR.IP-1, PR.PT-3 | | cis | 1.1.1.2 |
| |
|
Rule
Disable Mounting of hfs
[ref] |
To configure the system to prevent the hfs
kernel module from being loaded, add the following line to the file /etc/modprobe.d/hfs.conf:
install hfs /bin/false
This entry will cause a non-zero return value during a hfs module installation
and additionally convey the meaning of the entry to the user in form of an error message.
If you would like to omit a non-zero return value and an error message, you may want to add a different line instead
(both /bin/true and /bin/false are allowed by OVAL and will be accepted by the scan):
install hfs /bin/true
This effectively prevents usage of this uncommon filesystem. | | Rationale: | Linux kernel modules which implement filesystems that are not needed by the
local system should be disabled. | | Severity: | low | | Rule ID: | xccdf_org.ssgproject.content_rule_kernel_module_hfs_disabled | | References: | | cis-csc | 11, 14, 3, 9 | | cobit5 | BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06 | | cui | 3.4.6 | | isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3 | | isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6 | | iso27001-2013 | A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2 | | nist | CM-7(a), CM-7(b), CM-6(a) | | nist-csf | PR.IP-1, PR.PT-3 | | cis | 1.1.1.3 |
| |
|
Rule
Disable Mounting of hfsplus
[ref] |
To configure the system to prevent the hfsplus
kernel module from being loaded, add the following line to the file /etc/modprobe.d/hfsplus.conf:
install hfsplus /bin/false
This entry will cause a non-zero return value during a hfsplus module installation
and additionally convey the meaning of the entry to the user in form of an error message.
If you would like to omit a non-zero return value and an error message, you may want to add a different line instead
(both /bin/true and /bin/false are allowed by OVAL and will be accepted by the scan):
install hfsplus /bin/true
This effectively prevents usage of this uncommon filesystem. | | Rationale: | Linux kernel modules which implement filesystems that are not needed by the
local system should be disabled. | | Severity: | low | | Rule ID: | xccdf_org.ssgproject.content_rule_kernel_module_hfsplus_disabled | | References: | | cis-csc | 11, 14, 3, 9 | | cobit5 | BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06 | | cui | 3.4.6 | | isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3 | | isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6 | | iso27001-2013 | A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2 | | nist | CM-7(a), CM-7(b), CM-6(a) | | nist-csf | PR.IP-1, PR.PT-3 | | cis | 1.1.1.4 |
| |
|
Rule
Disable Mounting of jffs2
[ref] |
To configure the system to prevent the jffs2
kernel module from being loaded, add the following line to the file /etc/modprobe.d/jffs2.conf:
install jffs2 /bin/false
This entry will cause a non-zero return value during a jffs2 module installation
and additionally convey the meaning of the entry to the user in form of an error message.
If you would like to omit a non-zero return value and an error message, you may want to add a different line instead
(both /bin/true and /bin/false are allowed by OVAL and will be accepted by the scan):
install jffs2 /bin/true
This effectively prevents usage of this uncommon filesystem. | | Rationale: | Linux kernel modules which implement filesystems that are not needed by the
local system should be disabled. | | Severity: | low | | Rule ID: | xccdf_org.ssgproject.content_rule_kernel_module_jffs2_disabled | | References: | | cis-csc | 11, 14, 3, 9 | | cobit5 | BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06 | | cui | 3.4.6 | | isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3 | | isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6 | | iso27001-2013 | A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2 | | nist | CM-7(a), CM-7(b), CM-6(a) | | nist-csf | PR.IP-1, PR.PT-3 | | cis | 1.1.1.5 |
| |
|
Rule
Disable Modprobe Loading of USB Storage Driver
[ref] | To prevent USB storage devices from being used, configure the kernel module loading system
to prevent automatic loading of the USB storage driver.
To configure the system to prevent the usb-storage
kernel module from being loaded, add the following line to the file /etc/modprobe.d/usb-storage.conf:
install usb-storage /bin/false
This entry will cause a non-zero return value during a usb-storage module installation
and additionally convey the meaning of the entry to the user in form of an error message.
If you would like to omit a non-zero return value and an error message, you may want to add a different line instead
(both /bin/true and /bin/false are allowed by OVAL and will be accepted by the scan):
install usb-storage /bin/true
This will prevent the modprobe program from loading the usb-storage
module, but will not prevent an administrator (or another program) from using the
insmod program to load the module manually. | | Rationale: | USB storage devices such as thumb drives can be used to introduce
malicious software. | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_kernel_module_usb-storage_disabled | | References: | | cis-csc | 1, 12, 15, 16, 5 | | cobit5 | APO13.01, DSS01.04, DSS05.03, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10 | | cui | 3.1.21 | | hipaa | 164.308(a)(3)(i), 164.308(a)(3)(ii)(A), 164.310(d)(1), 164.310(d)(2), 164.312(a)(1), 164.312(a)(2)(iv), 164.312(b) | | isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4 | | isa-62443-2013 | SR 1.1, SR 1.10, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.6 | | iso27001-2013 | A.11.2.6, A.13.1.1, A.13.2.1, A.18.1.4, A.6.2.1, A.6.2.2, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3 | | nist | CM-7(a), CM-7(b), CM-6(a), MP-7 | | nist-csf | PR.AC-1, PR.AC-3, PR.AC-6, PR.AC-7 | | os-srg | SRG-OS-000114-GPOS-00059, SRG-OS-000378-GPOS-00163, SRG-OS-000480-GPOS-00227 | | app-srg-ctr | SRG-APP-000141-CTR-000315 | | cis | 1.1.1.10 | | pcidss4 | 3.4.2, 3.4 |
| |
|
| Group
Restrict Partition Mount Options
Group contains 19 rules |
[ref]
System partitions can be mounted with certain options
that limit what files on those partitions can do. These options
are set in the /etc/fstab configuration file, and can be
used to make certain types of malicious behavior more difficult. |
Rule
Add nodev Option to /dev/shm
[ref] | The nodev mount option can be used to prevent creation of device
files in /dev/shm. Legitimate character and block devices should
not exist within temporary directories like /dev/shm.
Add the nodev option to the fourth column of
/etc/fstab for the line which controls mounting of
/dev/shm. | | Rationale: | The only legitimate location for device files is the /dev directory
located on the root partition. The only exception to this is chroot jails. | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_mount_option_dev_shm_nodev | | References: | | cis-csc | 11, 13, 14, 3, 8, 9 | | cobit5 | APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS05.06, DSS06.06 | | isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3 | | isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6 | | iso27001-2013 | A.11.2.9, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.8.2.1, A.8.2.2, A.8.2.3, A.8.3.1, A.8.3.3, A.9.1.2 | | nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2 | | nist | CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7 | | nist-csf | PR.IP-1, PR.PT-2, PR.PT-3 | | os-srg | SRG-OS-000368-GPOS-00154 | | cis | 1.1.2.2.2 | | ism | 1409 |
| |
|
Rule
Add noexec Option to /dev/shm
[ref] | The noexec mount option can be used to prevent binaries
from being executed out of /dev/shm.
It can be dangerous to allow the execution of binaries
from world-writable temporary storage directories such as /dev/shm.
Add the noexec option to the fourth column of
/etc/fstab for the line which controls mounting of
/dev/shm. | | Rationale: | Allowing users to execute binaries from world-writable directories
such as /dev/shm can expose the system to potential compromise. | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_mount_option_dev_shm_noexec | | References: | | cis-csc | 11, 13, 14, 3, 8, 9 | | cobit5 | APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS05.06, DSS06.06 | | isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3 | | isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6 | | iso27001-2013 | A.11.2.9, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.8.2.1, A.8.2.2, A.8.2.3, A.8.3.1, A.8.3.3, A.9.1.2 | | nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2 | | nist | CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7 | | nist-csf | PR.IP-1, PR.PT-2, PR.PT-3 | | os-srg | SRG-OS-000368-GPOS-00154 | | cis | 1.1.2.2.4 | | ism | 1409 |
| |
|
Rule
Add nosuid Option to /dev/shm
[ref] | The nosuid mount option can be used to prevent execution
of setuid programs in /dev/shm. The SUID and SGID permissions should not
be required in these world-writable directories.
Add the nosuid option to the fourth column of
/etc/fstab for the line which controls mounting of
/dev/shm. | | Rationale: | The presence of SUID and SGID executables should be tightly controlled. Users
should not be able to execute SUID or SGID binaries from temporary storage partitions. | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_mount_option_dev_shm_nosuid | | References: | | cis-csc | 11, 13, 14, 3, 8, 9 | | cobit5 | APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS05.06, DSS06.06 | | isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3 | | isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6 | | iso27001-2013 | A.11.2.9, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.8.2.1, A.8.2.2, A.8.2.3, A.8.3.1, A.8.3.3, A.9.1.2 | | nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2 | | nist | CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7 | | nist-csf | PR.IP-1, PR.PT-2, PR.PT-3 | | os-srg | SRG-OS-000368-GPOS-00154 | | cis | 1.1.2.2.3 | | ism | 1409 |
| |
|
Rule
Add nodev Option to /home
[ref] | The nodev mount option can be used to prevent device files from
being created in /home.
Legitimate character and block devices should exist only in
the /dev directory on the root partition or within chroot
jails built for system services.
Add the nodev option to the fourth column of
/etc/fstab for the line which controls mounting of
/home. | | Rationale: | The only legitimate location for device files is the /dev directory
located on the root partition. The only exception to this is chroot jails. | | Severity: | unknown | | Rule ID: | xccdf_org.ssgproject.content_rule_mount_option_home_nodev | | References: | | |
|
Rule
Add nosuid Option to /home
[ref] | The nosuid mount option can be used to prevent
execution of setuid programs in /home. The SUID and SGID permissions
should not be required in these user data directories.
Add the nosuid option to the fourth column of
/etc/fstab for the line which controls mounting of
/home. | | Rationale: | The presence of SUID and SGID executables should be tightly controlled. Users
should not be able to execute SUID or SGID binaries from user home directory partitions. | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_mount_option_home_nosuid | | References: | | cis-csc | 11, 13, 14, 3, 8, 9 | | cobit5 | APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS05.06, DSS06.06 | | isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3 | | isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6 | | iso27001-2013 | A.11.2.9, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.8.2.1, A.8.2.2, A.8.2.3, A.8.3.1, A.8.3.3, A.9.1.2 | | nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2 | | nist | CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7 | | nist-csf | PR.IP-1, PR.PT-2, PR.PT-3 | | os-srg | SRG-OS-000368-GPOS-00154, SRG-OS-000480-GPOS-00227 | | anssi | R28 | | cis | 1.1.2.3.3 |
| |
|
Rule
Add nodev Option to /tmp
[ref] | The nodev mount option can be used to prevent device files from
being created in /tmp. Legitimate character and block devices
should not exist within temporary directories like /tmp.
Add the nodev option to the fourth column of
/etc/fstab for the line which controls mounting of
/tmp. | | Rationale: | The only legitimate location for device files is the /dev directory
located on the root partition. The only exception to this is chroot jails. | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_mount_option_tmp_nodev | | References: | | cis-csc | 11, 13, 14, 3, 8, 9 | | cobit5 | APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS05.06, DSS06.06 | | isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3 | | isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6 | | iso27001-2013 | A.11.2.9, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.8.2.1, A.8.2.2, A.8.2.3, A.8.3.1, A.8.3.3, A.9.1.2 | | nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2 | | nist | CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7 | | nist-csf | PR.IP-1, PR.PT-2, PR.PT-3 | | os-srg | SRG-OS-000368-GPOS-00154 | | cis | 1.1.2.1.2 |
| |
|
Rule
Add noexec Option to /tmp
[ref] | The noexec mount option can be used to prevent binaries
from being executed out of /tmp.
Add the noexec option to the fourth column of
/etc/fstab for the line which controls mounting of
/tmp. | | Rationale: | Allowing users to execute binaries from world-writable directories
such as /tmp should never be necessary in normal operation and
can expose the system to potential compromise. | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_mount_option_tmp_noexec | | References: | | cis-csc | 11, 13, 14, 3, 8, 9 | | cobit5 | APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS05.06, DSS06.06 | | isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3 | | isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6 | | iso27001-2013 | A.11.2.9, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.8.2.1, A.8.2.2, A.8.2.3, A.8.3.1, A.8.3.3, A.9.1.2 | | nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2 | | nist | CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7 | | nist-csf | PR.IP-1, PR.PT-2, PR.PT-3 | | os-srg | SRG-OS-000368-GPOS-00154 | | anssi | R28 | | cis | 1.1.2.1.4 |
| |
|
Rule
Add nosuid Option to /tmp
[ref] | The nosuid mount option can be used to prevent
execution of setuid programs in /tmp. The SUID and SGID permissions
should not be required in these world-writable directories.
Add the nosuid option to the fourth column of
/etc/fstab for the line which controls mounting of
/tmp. | | Rationale: | The presence of SUID and SGID executables should be tightly controlled. Users
should not be able to execute SUID or SGID binaries from temporary storage partitions. | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_mount_option_tmp_nosuid | | References: | | cis-csc | 11, 13, 14, 3, 8, 9 | | cobit5 | APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS05.06, DSS06.06 | | isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3 | | isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6 | | iso27001-2013 | A.11.2.9, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.8.2.1, A.8.2.2, A.8.2.3, A.8.3.1, A.8.3.3, A.9.1.2 | | nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2 | | nist | CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7 | | nist-csf | PR.IP-1, PR.PT-2, PR.PT-3 | | os-srg | SRG-OS-000368-GPOS-00154 | | anssi | R28 | | cis | 1.1.2.1.3 |
| |
|
Rule
Add nodev Option to /var/log/audit
[ref] | The nodev mount option can be used to prevent device files from
being created in /var/log/audit.
Legitimate character and block devices should exist only in
the /dev directory on the root partition or within chroot
jails built for system services.
Add the nodev option to the fourth column of
/etc/fstab for the line which controls mounting of
/var/log/audit. | | Rationale: | The only legitimate location for device files is the /dev directory
located on the root partition. The only exception to this is chroot jails. | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_mount_option_var_log_audit_nodev | | References: | | nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2 | | nist | CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7 | | nist-csf | PR.IP-1, PR.PT-2, PR.PT-3 | | ospp | FMT_SMF_EXT.1 | | os-srg | SRG-OS-000368-GPOS-00154 | | cis | 1.1.2.7.2 |
| |
|
Rule
Add noexec Option to /var/log/audit
[ref] | The noexec mount option can be used to prevent binaries
from being executed out of /var/log/audit.
Add the noexec option to the fourth column of
/etc/fstab for the line which controls mounting of
/var/log/audit. | | Rationale: | Allowing users to execute binaries from directories containing audit log files
such as /var/log/audit should never be necessary in normal operation and
can expose the system to potential compromise. | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_mount_option_var_log_audit_noexec | | References: | | nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2 | | nist | CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7 | | nist-csf | PR.IP-1, PR.PT-2, PR.PT-3 | | ospp | FMT_SMF_EXT.1 | | os-srg | SRG-OS-000368-GPOS-00154 | | cis | 1.1.2.7.4 |
| |
|
Rule
Add nosuid Option to /var/log/audit
[ref] | The nosuid mount option can be used to prevent
execution of setuid programs in /var/log/audit. The SUID and SGID permissions
should not be required in directories containing audit log files.
Add the nosuid option to the fourth column of
/etc/fstab for the line which controls mounting of
/var/log/audit. | | Rationale: | The presence of SUID and SGID executables should be tightly controlled. Users
should not be able to execute SUID or SGID binaries from partitions
designated for audit log files. | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_mount_option_var_log_audit_nosuid | | References: | | nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2 | | nist | CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7 | | nist-csf | PR.IP-1, PR.PT-2, PR.PT-3 | | ospp | FMT_SMF_EXT.1 | | os-srg | SRG-OS-000368-GPOS-00154 | | cis | 1.1.2.7.3 |
| |
|
Rule
Add nodev Option to /var/log
[ref] | The nodev mount option can be used to prevent device files from
being created in /var/log.
Legitimate character and block devices should exist only in
the /dev directory on the root partition or within chroot
jails built for system services.
Add the nodev option to the fourth column of
/etc/fstab for the line which controls mounting of
/var/log. | | Rationale: | The only legitimate location for device files is the /dev directory
located on the root partition. The only exception to this is chroot jails. | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_mount_option_var_log_nodev | | References: | | nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2 | | nist | CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7 | | nist-csf | PR.IP-1, PR.PT-2, PR.PT-3 | | os-srg | SRG-OS-000368-GPOS-00154 | | cis | 1.1.2.6.2 |
| |
|
Rule
Add noexec Option to /var/log
[ref] | The noexec mount option can be used to prevent binaries
from being executed out of /var/log.
Add the noexec option to the fourth column of
/etc/fstab for the line which controls mounting of
/var/log. | | Rationale: | Allowing users to execute binaries from directories containing log files
such as /var/log should never be necessary in normal operation and
can expose the system to potential compromise. | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_mount_option_var_log_noexec | | References: | | nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2 | | nist | CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7 | | nist-csf | PR.IP-1, PR.PT-2, PR.PT-3 | | os-srg | SRG-OS-000368-GPOS-00154 | | anssi | R28 | | cis | 1.1.2.6.4 |
| |
|
Rule
Add nosuid Option to /var/log
[ref] | The nosuid mount option can be used to prevent
execution of setuid programs in /var/log. The SUID and SGID permissions
should not be required in directories containing log files.
Add the nosuid option to the fourth column of
/etc/fstab for the line which controls mounting of
/var/log. | | Rationale: | The presence of SUID and SGID executables should be tightly controlled. Users
should not be able to execute SUID or SGID binaries from partitions
designated for log files. | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_mount_option_var_log_nosuid | | References: | | nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2 | | nist | CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7 | | nist-csf | PR.IP-1, PR.PT-2, PR.PT-3 | | os-srg | SRG-OS-000368-GPOS-00154 | | anssi | R28 | | cis | 1.1.2.6.3 |
| |
|
Rule
Add nodev Option to /var
[ref] | The nodev mount option can be used to prevent device files from
being created in /var.
Legitimate character and block devices should exist only in
the /dev directory on the root partition or within chroot
jails built for system services.
Add the nodev option to the fourth column of
/etc/fstab for the line which controls mounting of
/var. | | Rationale: | The only legitimate location for device files is the /dev directory
located on the root partition. The only exception to this is chroot jails. | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_mount_option_var_nodev | | References: | | nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2 | | nist | CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7 | | nist-csf | PR.IP-1, PR.PT-2, PR.PT-3 | | os-srg | SRG-OS-000368-GPOS-00154 | | cis | 1.1.2.4.2 |
| |
|
Rule
Add nosuid Option to /var
[ref] | The nosuid mount option can be used to prevent
execution of setuid programs in /var. The SUID and SGID permissions
should not be required for this directory.
Add the nosuid option to the fourth column of
/etc/fstab for the line which controls mounting of
/var. | | Rationale: | The presence of SUID and SGID executables should be tightly controlled. | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_mount_option_var_nosuid | | References: | | |
|
Rule
Add nodev Option to /var/tmp
[ref] | The nodev mount option can be used to prevent device files from
being created in /var/tmp. Legitimate character and block devices
should not exist within temporary directories like /var/tmp.
Add the nodev option to the fourth column of
/etc/fstab for the line which controls mounting of
/var/tmp. | | Rationale: | The only legitimate location for device files is the /dev directory
located on the root partition. The only exception to this is chroot jails. | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_mount_option_var_tmp_nodev | | References: | | |
|
Rule
Add noexec Option to /var/tmp
[ref] | The noexec mount option can be used to prevent binaries
from being executed out of /var/tmp.
Add the noexec option to the fourth column of
/etc/fstab for the line which controls mounting of
/var/tmp. | | Rationale: | Allowing users to execute binaries from world-writable directories
such as /var/tmp should never be necessary in normal operation and
can expose the system to potential compromise. | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_mount_option_var_tmp_noexec | | References: | | |
|
Rule
Add nosuid Option to /var/tmp
[ref] | The nosuid mount option can be used to prevent
execution of setuid programs in /var/tmp. The SUID and SGID permissions
should not be required in these world-writable directories.
Add the nosuid option to the fourth column of
/etc/fstab for the line which controls mounting of
/var/tmp. | | Rationale: | The presence of SUID and SGID executables should be tightly controlled. Users
should not be able to execute SUID or SGID binaries from temporary storage partitions. | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_mount_option_var_tmp_nosuid | | References: | | |
|
| Group
Restrict Programs from Dangerous Execution Patterns
Group contains 2 groups and 8 rules |
[ref]
The recommendations in this section are designed to
ensure that the system's features to protect against potentially
dangerous program execution are activated.
These protections are applied at the system initialization or
kernel level, and defend against certain types of badly-configured
or compromised programs. |
| Group
Disable Core Dumps
Group contains 4 rules |
[ref]
A core dump file is the memory image of an executable
program when it was terminated by the operating system due to
errant behavior. In most cases, only software developers
legitimately need to access these files. The core dump files may
also contain sensitive information, or unnecessarily occupy large
amounts of disk space.
Once a hard limit is set in /etc/security/limits.conf, or
to a file within the /etc/security/limits.d/ directory, a
user cannot increase that limit within his or her own session. If access
to core dumps is required, consider restricting them to only
certain users or groups. See the limits.conf man page for more
information.
The core dumps of setuid programs are further protected. The
sysctl variable fs.suid_dumpable controls whether
the kernel allows core dumps from these programs at all. The default
value of 0 is recommended. |
Rule
Disable core dump backtraces
[ref] | The ProcessSizeMax option in [Coredump] section
of /etc/systemd/coredump.conf or in a drop-in file under
/etc/systemd/coredump.conf.d/ specifies the maximum size in bytes
of a core which will be processed. Core dumps exceeding this size may be
stored, but the backtrace will not be generated. Warning:
If the /etc/systemd/coredump.conf file or a drop-in file under /etc/systemd/coredump.conf.d/
does not already contain the [Coredump] section,
the value will not be configured correctly. | | Rationale: | A core dump includes a memory image taken at the time the operating system
terminates an application. The memory image could contain sensitive data
and is generally useful only for developers or system operators trying to
debug problems.
Enabling core dumps on production systems is not recommended,
however there may be overriding operational requirements to enable advanced
debugging. Permitting temporary enablement of core dumps during such situations
should be reviewed through local needs and policy. | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_coredump_disable_backtraces | | References: | | |
|
Rule
Disable storing core dump
[ref] | The Storage option in [Coredump] section
of /etc/systemd/coredump.conf or a drop-in file in
/etc/systemd/coredump.conf.d/*.conf
can be set to none to disable storing core dumps permanently. Warning:
If the /etc/systemd/coredump.conf file or a drop-in file under /etc/systemd/coredump.conf.d/
does not already contain the [Coredump] section,
the value will not be configured correctly. | | Rationale: | A core dump includes a memory image taken at the time the operating system
terminates an application. The memory image could contain sensitive data
and is generally useful only for developers or system operators trying to
debug problems. Enabling core dumps on production systems is not recommended,
however there may be overriding operational requirements to enable advanced
debugging. Permitting temporary enablement of core dumps during such situations
should be reviewed through local needs and policy. | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_coredump_disable_storage | | References: | | |
|
Rule
Disable Core Dumps for All Users
[ref] | To disable core dumps for all users, add the following line to
/etc/security/limits.conf, or to a file within the
/etc/security/limits.d/ directory:
* hard core 0
| | Rationale: | A core dump includes a memory image taken at the time the operating system
terminates an application. The memory image could contain sensitive data and is generally useful
only for developers trying to debug problems. | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_disable_users_coredumps | | References: | | cis-csc | 1, 12, 13, 15, 16, 2, 7, 8 | | cobit5 | APO13.01, BAI04.04, DSS01.03, DSS03.05, DSS05.07 | | isa-62443-2013 | SR 6.2, SR 7.1, SR 7.2 | | iso27001-2013 | A.12.1.3, A.17.2.1 | | nist | CM-6, SC-7(10) | | nist-csf | DE.CM-1, PR.DS-4 | | os-srg | SRG-OS-000480-GPOS-00227 | | cis | 1.5.11 | | pcidss4 | 3.3.1.1, 3.3.1, 3.3 |
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Rule
Disable Core Dumps for SUID programs
[ref] | To set the runtime status of the fs.suid_dumpable kernel parameter, run the following command: $ sudo sysctl -w fs.suid_dumpable=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: fs.suid_dumpable = 0
| | Rationale: | The core dump of a setuid program is more likely to contain
sensitive data, as the program itself runs with greater privileges than the
user who initiated execution of the program. Disabling the ability for any
setuid program to write a core file decreases the risk of unauthorized access
of such data. | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_sysctl_fs_suid_dumpable | | References: | | hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3), 164.308(a)(4), 164.310(b), 164.310(c), 164.312(a), 164.312(e) | | nist | SI-11(a), SI-11(b) | | anssi | R14 | | cis | 1.5.4 | | pcidss4 | 3.3.1.1, 3.3.1, 3.3 |
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| Group
Enable ExecShield
Group contains 2 rules |
[ref]
ExecShield describes kernel features that provide
protection against exploitation of memory corruption errors such as buffer
overflows. These features include random placement of the stack and other
memory regions, prevention of execution in memory that should only hold data,
and special handling of text buffers. These protections are enabled by default
on 32-bit systems and controlled through sysctl variables
kernel.exec-shield and kernel.randomize_va_space. On the latest
64-bit systems, kernel.exec-shield cannot be enabled or disabled with
sysctl. |
Rule
Restrict Exposed Kernel Pointer Addresses Access
[ref] | To set the runtime status of the kernel.kptr_restrict kernel parameter, run the following command: $ sudo sysctl -w kernel.kptr_restrict=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: kernel.kptr_restrict = 1
| | Rationale: | Exposing kernel pointers (through procfs or seq_printf()) exposes kernel
writeable structures which may contain functions pointers. If a write vulnerability
occurs in the kernel, allowing write access to any of this structure, the kernel can
be compromised. This option disallow any program without the CAP_SYSLOG capability
to get the addresses of kernel pointers by replacing them with 0. | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_sysctl_kernel_kptr_restrict | | References: | | nerc-cip | CIP-002-5 R1.1, CIP-002-5 R1.2, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 4.1, CIP-004-6 4.2, CIP-004-6 R2.2.3, CIP-004-6 R2.2.4, CIP-004-6 R2.3, CIP-004-6 R4, CIP-005-6 R1, CIP-005-6 R1.1, CIP-005-6 R1.2, CIP-007-3 R3, CIP-007-3 R3.1, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.1.3, CIP-007-3 R5.2.1, CIP-007-3 R5.2.3, CIP-007-3 R8.4, CIP-009-6 R.1.1, CIP-009-6 R4 | | nist | SC-30, SC-30(2), SC-30(5), CM-6(a) | | ospp | FMT_SMF_EXT.1 | | os-srg | SRG-OS-000132-GPOS-00067, SRG-OS-000433-GPOS-00192, SRG-OS-000480-GPOS-00227 | | anssi | R9 | | cis | 1.5.8 | | ism | 1409 |
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Rule
Enable Randomized Layout of Virtual Address Space
[ref] | To set the runtime status of the kernel.randomize_va_space kernel parameter, run the following command: $ sudo sysctl -w kernel.randomize_va_space=2
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: kernel.randomize_va_space = 2
| | Rationale: | Address space layout randomization (ASLR) makes it more difficult for an
attacker to predict the location of attack code they have introduced into a
process's address space during an attempt at exploitation. Additionally,
ASLR makes it more difficult for an attacker to know the location of
existing code in order to re-purpose it using return oriented programming
(ROP) techniques. | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_sysctl_kernel_randomize_va_space | | References: | | cui | 3.1.7 | | hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3), 164.308(a)(4), 164.310(b), 164.310(c), 164.312(a), 164.312(e) | | nerc-cip | CIP-002-5 R1.1, CIP-002-5 R1.2, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 4.1, CIP-004-6 4.2, CIP-004-6 R2.2.3, CIP-004-6 R2.2.4, CIP-004-6 R2.3, CIP-004-6 R4, CIP-005-6 R1, CIP-005-6 R1.1, CIP-005-6 R1.2, CIP-007-3 R3, CIP-007-3 R3.1, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.1.3, CIP-007-3 R5.2.1, CIP-007-3 R5.2.3, CIP-007-3 R8.4, CIP-009-6 R.1.1, CIP-009-6 R4 | | nist | SC-30, SC-30(2), CM-6(a) | | pcidss | Req-2.2.1 | | os-srg | SRG-OS-000433-GPOS-00193, SRG-OS-000480-GPOS-00227 | | app-srg-ctr | SRG-APP-000450-CTR-001105 | | anssi | R9 | | cis | 1.5.9 | | ism | 1409 | | pcidss4 | 3.3.1.1, 3.3.1, 3.3 |
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Rule
Restrict Access to Kernel Message Buffer
[ref] | To set the runtime status of the kernel.dmesg_restrict kernel parameter, run the following command: $ sudo sysctl -w kernel.dmesg_restrict=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: kernel.dmesg_restrict = 1
| | Rationale: | Unprivileged access to the kernel syslog can expose sensitive kernel
address information. | | Severity: | low | | Rule ID: | xccdf_org.ssgproject.content_rule_sysctl_kernel_dmesg_restrict | | References: | | cui | 3.1.5 | | hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3), 164.308(a)(4), 164.310(b), 164.310(c), 164.312(a), 164.312(e) | | nist | SI-11(a), SI-11(b) | | ospp | FMT_SMF_EXT.1 | | os-srg | SRG-OS-000132-GPOS-00067, SRG-OS-000138-GPOS-00069 | | app-srg-ctr | SRG-APP-000243-CTR-000600 | | anssi | R9 | | cis | 1.5.5 | | ism | 1546 |
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Rule
Restrict usage of ptrace to descendant processes
[ref] | To set the runtime status of the kernel.yama.ptrace_scope kernel parameter, run the following command: $ sudo sysctl -w kernel.yama.ptrace_scope=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: kernel.yama.ptrace_scope = 1
| | Rationale: | Unrestricted usage of ptrace allows compromised binaries to run ptrace
on another processes of the user. Like this, the attacker can steal
sensitive information from the target processes (e.g. SSH sessions, web browser, ...)
without any additional assistance from the user (i.e. without resorting to phishing).
| | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_sysctl_kernel_yama_ptrace_scope | | References: | | |
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