The STARTTLS implementation in qmail-smtpd.c in qmail-smtpd in the netqmail-1.06-tls patch for netqmail 1.06 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. Per: http://cwe.mitre.org/data/definitions/77.html
Improper Neutralization of Special Elements used in a Command ('Command Injection')
Publication date: Thu, 17 Mar 2011 03:55:00 +0000