Buffer overflow in the ARTpost function in art.c in the control message handling code for INN 2.4.0 may allow remote attackers to execute arbitrary code.

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.