CVE-2011-1506: Kerio Connect

Medium severity, CVSS 6.8. EPSS: 2.5% chance of exploitation in the next 30 days.

The STARTTLS implementation in Kerio Connect 7.1.4 build 2985 and MailServer 6.x 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. NOTE: some of these details are obtained from third party information.

Affected products

• Kerio Connect: version 7.1.4 only
• Kerio Kerio Mailserver: version 5.0 only; version 5.1 only; version 5.1.1 only; version 5.6.3 only; version 5.6.4 only; version 5.6.5 only; …

Published 2011-03-22. Last modified 2026-06-16.