Cisco StarOS for Cisco ASR 5000 Series HAMGR Service Proxy Mobile IPv6 Processing Denial of Service Vulnerability

A vulnerability in proxy mobile (PM) IPv6 processing of Cisco StarOS for Cisco ASR 5000 Series devices could allow an unauthenticated, remote attacker to cause a reload of the hamgr service on the affected device.

The vulnerability is due to improper processing of malformed IPv6 PM packets. An attacker could exploit this vulnerability by sending a number of malformed IPv6 PM packets to an affected device. An exploit could allow the attacker to cause the hamgr service on the affected device to reload. A reload of the hamgr service may cause new calls to fail 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 IPv6 PM packets to the targeted 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.