The nullfs implementation in sys/fs/nullfs/null_vnops.c in the kernel in FreeBSD 8.3 through 9.2 allows local users with certain permissions to bypass access restrictions via a hardlink in a nullfs instance to a file in a different instance.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Freebsd | Freebsd | 8.0 (including) | 8.0 (including) |
| Freebsd | Freebsd | 8.3 (including) | 8.3 (including) |
| Freebsd | Freebsd | 8.4 (including) | 8.4 (including) |
| Freebsd | Freebsd | 9.0 (including) | 9.0 (including) |
| Freebsd | Freebsd | 9.1 (including) | 9.1 (including) |
| Freebsd | Freebsd | 9.2 (including) | 9.2 (including) |