BaselineWatch
Desk
Your fleet and your work Fleetyour releases and the hardware they run onTriagewhat needs a decisionWatchlistthe products and platforms you runSaved searchesthe lists you come back to
This instance Sourceswhat is read, how often, under what termsDigestthe daily or weekly summary, and alerts
How it is drawn Appearancethe look and the colour schemeBrandingthe mark this instance wears
Owner sign-in

RHEL-10-701080 RHEL 10 must enable kernel parameters to enforce discretionary access control (DAC) on symlinks.

DISA STIG library V1R3
All changes in this version
first version loaded CAT II

Maps to AC-3(4), AC-6(10) via CCI-002165, CCI-002235

Title

RHEL 10 must enable kernel parameters to enforce discretionary access control (DAC) on symlinks.

Control

Verify RHEL 10 is configured to enable DAC on symlinks. Check the status of the "fs.protected_symlinks" kernel parameter with the following command: $ sudo sysctl fs.protected_symlinks fs.protected_symlinks = 1 If "fs.protected_symlinks" is not set to "1" or is missing, this is a finding.

Discussion

By enabling the "fs.protected_symlinks" kernel parameter, symbolic links are permitted to be followed only when outside a sticky world-writable directory, or when the user identifier (UID) of the link and follower match, or when the directory owner matches the symlink's owner. Disallowing such symlinks helps mitigate vulnerabilities based on insecure file systems accessed by privileged programs, avoiding an exploitation vector exploiting unsafe use of open() or creat(). Satisfies: SRG-OS-000312-GPOS-00122, SRG-OS-000312-GPOS-00123, SRG-OS-000324-GPOS-00125

Related controls

CCI-002165, CCI-002235

Fix

Configure RHEL 10 to enable DAC on symlinks with the following: Create a drop-in if it does not already exist: $ sudo vi /etc/sysctl.d/99-fs_protected_symlinks.conf Add the following to the file: fs.protected_symlinks = 1 Reload settings from all system configuration files with the following command: $ sudo sysctl --system