Detections
Analytics

1.38 ALMA-09-007060

Information

AlmaLinux OS 9 must enable kernel parameters to enforce discretionary access control on hardlinks.

GROUP ID: V-269144
RULE ID: SV-269144r1050026

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().

Solution

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

See Also

https://workbench.cisecurity.org/benchmarks/27039

Item Details

Category: ACCESS CONTROL

References: 800-53|AC-6(10), CCI|CCI-002235, Rule-ID|SV-269144r1050026_rule, STIG-ID|ALMA-09-007060, Vuln-ID|V-269144

Plugin: Unix

Control ID: 17b57943f4fb3b475c41ad5f4cc2f81161e07a59e6970a79b4f26975bab42bce