Cisco Firewall Services Module (FWSM) Software contains a vulnerability that could allow an unauthenticated, remote attacker to cause a reload of an affected system.
The vulnerability is due to a race condition when releasing the memory allocated by the cut-through proxy function.
An attacker could exploit this vulnerability by sending traffic to match the condition that triggers cut-through proxy authentication.
Cisco has released free software updates that address this vulnerability. Workarounds that mitigate the vulnerability are not available.
This advisory is available at the following link: http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20140219-fwsm