ipfw and ip6fw in FreeBSD 4.2 and earlier allows remote attackers to bypass access restrictions by setting the ECE flag in a TCP packet, which makes the packet appear to be part of an established connection.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Freebsd | Freebsd | 3.0 (including) | 3.0 (including) |
| Freebsd | Freebsd | 3.1 (including) | 3.1 (including) |
| Freebsd | Freebsd | 3.3 (including) | 3.3 (including) |
| Freebsd | Freebsd | 3.4 (including) | 3.4 (including) |
| Freebsd | Freebsd | 3.5 (including) | 3.5 (including) |
| Freebsd | Freebsd | 3.5.1 (including) | 3.5.1 (including) |
| Freebsd | Freebsd | 4.0 (including) | 4.0 (including) |
| Freebsd | Freebsd | 4.0-alpha (including) | 4.0-alpha (including) |
| Freebsd | Freebsd | 4.1 (including) | 4.1 (including) |
| Freebsd | Freebsd | 4.1.1 (including) | 4.1.1 (including) |
| Freebsd | Freebsd | 4.2 (including) | 4.2 (including) |