Cisco IOS Software 802.1x Multiple-Authentication Port Authentication Bypass Vulnerability

A vulnerability in the 802.1x multiple-authentication (multi-auth) feature of Cisco IOS Software could allow an unauthenticated, adjacent attacker to bypass the authentication phase on an 802.1x multi-auth port.

The vulnerability is due to a logic change error introduced into the code. An attacker could exploit this vulnerability by trying to access an 802.1x multi-auth port after a successful supplicant has authenticated. An exploit could allow the attacker to bypass the 802.1x access controls and obtain access to the network.
There are no workarounds that address this vulnerability.

This advisory is available at the following link:
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180328-dot1x [“https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180328-dot1x”]