Cisco Nexus 9000 Series Switches Access List Bypass Vulnerability

A vulnerability in the implementation of the access list logging feature of Cisco Nexus 9000 Series Switches could allow an unauthenticated, remote attacker to bypass the access list restriction for the logged traffic. The vulnerability is due to insufficient policy checks for the logged packets. An attacker could exploit this vulnerability by sending a flood of denied packets that match an access list entry with the log keyword. An exploit could allow the attacker to bypass the access control list for a small percentage of the packets, which would otherwise have been dropped. Cisco has confirmed the vulnerability in a security notice and released software updates. Cisco indicates through the CVSS score that functional exploit code exists. However, the code is not known to be publicly available.

Checks if a vulnerable version is present on the target host.

See the referenced vendor advisory for a solution.