Cisco IOS XE Software Malformed L2TP Packet Vulnerability

A vulnerability in the Layer 2 Tunneling Protocol (L2TP) module of Cisco IOS XE on Cisco ASR 1000 Series Routers could allow an authenticated, remote attacker to cause a reload of the processing ESP card.

The vulnerability occurs during the processing of a malformed L2TP packet. An attacker could exploit this vulnerability by sending malformed L2TP packets over an established L2TP session. An exploit could allow the attacker to cause a reload of the affected ESP card.

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

To exploit this vulnerability, an attacker must authenticate to a targeted device. This access requirement decreases the likelihood of a successful exploit attempt.

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