CVE-2018-0136

Name of the Vulnerable Software and Affected Versions: Cisco IOS XR Software Release 5.3.4 for the Cisco Aggregation Services Router (ASR) 9000 Series

Description: A vulnerability in the IPv6 subsystem could allow an unauthenticated, remote attacker to trigger a reload of one or more Trident-based line cards, resulting in a denial of service (DoS) condition. The issue is due to incorrect handling of IPv6 packets with a fragment header extension. An attacker could exploit this by sending IPv6 packets designed to trigger the issue either to or through the Trident-based line card. A successful exploit could allow the attacker to trigger a reload of Trident-based line cards, resulting in a DoS during the period of time the line card takes to restart.

Recommendations: Apply the software maintenance upgrade (SMU) that addresses this vulnerability. Alternatively, upgrade to service pack 7 for Cisco IOS XR Software Release 5.3.4.