AlmaLinux OS 9 must enable kernel parameters to enforce discretionary access control on hardlinks.
An XCCDF Rule
Description
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 unsecure file systems accessed by privileged programs, avoiding an exploitation vector exploiting unsafe use of open() or creat().
- ID
- SV-269144r1050026_rule
- Version
- ALMA-09-007060
- Severity
- Medium
- References
- Updated
Remediation Templates
A Manual Procedure
Configure AlmaLinux OS 9 to enable DAC on hardlinks with the following command:
$ echo "fs.protected_hardlinks = 1" > /etc/sysctl.d/60-hardlinks.conf
Load settings from all system configuration files with the following command:
$ sysctl –system