Cisco Adaptive Security Appliance Software SIP Inspection Memory Leak Vulnerability

A vulnerability in the Session Initiation Protocol (SIP) inspection engine code could allow an
unauthenticated, remote attacker to cause a slow memory leak, which may cause
instability on the affected system.

The vulnerability is due to improper
handling of SIP packets inspected by the Cisco Adaptive Security Appliance (ASA) SIP inspection engine. An
attacker could exploit this vulnerability by sending crafted SIP packets
through the affected system. An exploit could allow the attacker to cause
allocated memory not to be returned during the attack. This may cause system
instability and a partial denial of service (DoS) condition.

Cisco has confirmed the vulnerability in a security notice and released software updates.

To exploit this vulnerability, an attacker may need access to trusted, internal networks to send crafted SIP packets through a targeted device. This access requirement may reduce the possibility of a successful exploit.

Cisco indicates through the CVSS score that functional exploit code exists; however, the code is not known to be publicly available.