mgetty-sendfax creates the lockfile directory: [kaboom@hanuman outgoing]$ ls -ld /var/spool/fax/outgoing/locks drwxrwxrwx 2 root root 1024 Mar 28 17:27 /var/spool/fax/outgoing/locks [kaboom@hanuman outgoing]$ At a mimimum, this directory should instead be chmod 1777 to prevent users from tampering with others' lock files.
Closing this -- in 8 this directory is now sticky