A vulnerability in the EAP-FAST authentication module of Cisco Secure Access Control Server (ACS) versions 4.0 through 18.104.22.168 could allow an unauthenticated, remote attacker to execute arbitrary commands on the Cisco Secure ACS server. This vulnerability is only present when Cisco Secure ACS is configured as a RADIUS server.
The vulnerability is due to improper parsing of user identities used for EAP-FAST authentication. An attacker could exploit this vulnerability by sending crafted EAP-FAST packets to an affected device. An exploit could allow the attacker to execute arbitrary commands on the Cisco Secure ACS server and take full control of the affected server.
There are no workarounds for this vulnerability.
Cisco has released software updates that address this vulnerability. This advisory is available at the following link: