CVE-2011-0411: Postfix

Medium severity, CVSS 6.8. EPSS: 16.3% chance of exploitation in the next 30 days.

The STARTTLS implementation in Postfix 2.4.x before 2.4.16, 2.5.x before 2.5.12, 2.6.x before 2.6.9, and 2.7.x before 2.7.3 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.

Affected products

• Postfix Postfix: version 2.4 only; version 2.4.0 only; version 2.4.1 only; version 2.4.2 only; version 2.4.3 only; version 2.4.4 only; …

Published 2011-03-16. Last modified 2026-06-16.