Detections
Analytics

1.303 OL09-00-002401

Information

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

GROUP ID: V-271740
RULE ID: SV-271740r1091932

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 system accessed by privileged programs, avoiding an exploitation vector exploiting unsafe use of open() or creat().

Satisfies: SRG-OS-000312-GPOS-00123, SRG-OS-000324-GPOS-00125

Solution

Configure OL 9 to enable DAC on hardlinks with the following:

Add or edit the following line in a system configuration file in the "/etc/sysctl.d/" directory:

fs.protected_hardlinks = 1

Load settings from all system configuration files with the following command:

$ sudo sysctl --system

See Also

https://workbench.cisecurity.org/benchmarks/27024

Item Details

Category: ACCESS CONTROL

References: 800-53|AC-3(4), 800-53|AC-6(10), CCI|CCI-002165, CCI|CCI-002235, Rule-ID|SV-271740r1091932_rule, STIG-ID|OL09-00-002401, Vuln-ID|V-271740

Plugin: Unix

Control ID: 17786fada6632cc4cc135f117ff580c4d5e030f428b830fd51c60144e66333a4