The STARTTLS implementation in WatchGuard XCS 9.0 and 9.1 does not properly restrict I/O buffering, which allows man-in-the-middle attackers to insert commands into encrypted SMTP sessions by sending a cleartext command that is processed after TLS is in place, related to a plaintext command injection attack, a similar issue to CVE-2011-0411.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Xcs | Watchguard | 9.0 (including) | 9.0 (including) |
| Xcs | Watchguard | 9.1 (including) | 9.1 (including) |