Cisco Web Security Appliance HTTP POST Denial of Service Vulnerability

A vulnerability that occurs when parsing an HTTP POST request with Cisco AsyncOS for Cisco Web Security Appliance (WSA) could allow an unauthenticated, remote attacker to cause a denial of service (DoS) vulnerability due to the proxy process becoming unresponsive.

The vulnerability is due to a lack of proper input validation of the packets that make up the HTTP POST request. An attacker could exploit this vulnerability by sending a crafted HTTP POST request to the affected device. An exploit could allow the attacker to cause a DoS condition due to the proxy process becoming unresponsive and the WSA reloading.

Cisco has released software updates that address this vulnerability. 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-20160518-wsa1[“https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20160518-wsa1”]