Cisco StarOS for Cisco ASR 5000 Series HTTP Packet Processing Denial of Service Vulnerability

A vulnerability in HTTP packet processing of Cisco StarOS for Cisco ASR 5000 Series devices could allow an unauthenticated, remote attacker to cause a reload of the session manager service on the affected device.

The vulnerability is due to improper processing of malformed HTTP packets. An attacker could exploit this vulnerability by sending a number of malformed HTTP packets to the affected device. An exploit could allow the attacker to cause the session manager service on the device to reload. A reload of the session manager service may cause loss of packets during a recovery period, resulting in a denial of service (DoS) condition.

Cisco has confirmed the vulnerability and released software updates.

To exploit this vulnerability, an attacker may need access to trusted, internal networks to send malformed HTTP packets to the affected device. This access requirement may reduce the likelihood 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.