V-258903

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 mitigate vulnerabilities based on insecure file system accessed by privileged programs, avoiding an exploitation vector exploiting unsafe use of open() or creat().

Check Content

At the command line, run the following command to verify hardlink protection is enabled:

# /sbin/sysctl fs.protected_hardlinks

Example result:

fs.protected_hardlinks = 1

If the "fs.protected_hardlinks" kernel parameter is not set to "1", this is a finding.