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-10-701070 RHEL 10 must enable kernel parameters to enforce discretionary access control (DAC) on hardlinks.

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 hardlinks.

Control

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

Discussion

By enabling the "fs.protected_hardlinks" kernel parameter, users can no longer create soft or hard links to files they do not own. Disallowing such hardlinks mitigates 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 hardlinks. Create a drop-in if it does not already exist: $ sudo vi /etc/sysctl.d/99-fs_protected_hardlinks.conf Add the following to the file: fs.protected_hardlinks = 1 Reload settings from all system configuration files with the following command: $ sudo sysctl --system