Cisco ASR901 Crafted IPv4 Packet Denial of Service Vulnerability

A vulnerability in Internet Protocol version 4 (IPv4) packet processing of the Cisco ASR901 could allow an unauthenticated, remote attacker to flood packets to the ASR901 CPU.

The vulnerability is due to punting crafted IPv4 packets to the CPU for processing. An attacker could exploit this vulnerability by sending specifically crafted IPv4 packets. An exploit could allow the attacker to flood traffic to the CPU of the ASR901, which would result in BGP neighbor flaps.

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 behind a firewall to send crafted 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.