V-258841

Discussion

By enabling the fs.protected_symlinks kernel parameter, symbolic links are permitted to be followed only when outside a sticky world-writable directory, or when the UID of the link and follower match, or when the directory owner matches the symlink's owner. Disallowing such symlinks helps 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 symlink protection is enabled:

# /sbin/sysctl fs.protected_symlinks

Example result:

fs.protected_symlinks = 1

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