The STARTTLS implementation in nnrpd in INN before 2.5.3 does not properly restrict I/O buffering, which allows man-in-the-middle attackers to insert commands into encrypted 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.
http://www.mandriva.com/security/advisories?name=MDVSA-2012:156
http://secunia.com/advisories/50661
http://lists.opensuse.org/opensuse-updates/2012-09/msg00058.html