Guest

Preview Tool

Cisco Bug: CSCur28305 - Cisco Web Security Appliance Connection Denial of Service Vulnerability

Last Modified

Jan 27, 2017

Products (1)

  • Cisco Web Security Appliance

Known Affected Releases

8.0.6-101

Description (partial)

Symptom:
A vulnerability in Cisco AsyncOS for the Cisco Web Security Appliance (WSA) when the software handles a specific HTTP response code could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an appliance because the appliance runs out of system memory.

The vulnerability occurs because the software does not free client and server connection memory and system file descriptors when a certain HTTP response code is received in the HTTP request. An attacker could exploit this vulnerability by sending a crafted HTTP request to the affected device. An exploit could allow the attacker to cause a DoS condition because the appliance runs out of system memory. When this happens, the device can no longer accept new incoming connection requests.

Cisco has released software updates that address this vulnerability. A workaround that addresses this vulnerability is also available.
 
This advisory is available at the following link:

http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20160518-wsa4

Conditions:
Please refer to the advisory.
Bug details contain sensitive information and therefore require a Cisco.com 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.