Preview Tool

Cisco Bug: CSCuj16824 - Cisco FWSM Cut-Through Proxy Denial of Service Vulnerability

Last Modified

Aug 11, 2015

Products (1)

  • Cisco Catalyst 6500 Series Firewall Services Module

Known Affected Releases


Description (partial)

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:

See published Cisco Security Advisory
Bug details contain sensitive information and therefore require a account to be viewed.

Bug Details Include

  • Full Description (including symptoms, conditions and workarounds)
  • Status
  • Severity
  • Known Fixed Releases
  • Related Community Discussions
  • Number of Related Support Cases
Bug information is viewable for customers and partners who have a service contract. Registered users can view up to 200 bugs per month without a service contract.