Cisco Security Advisory: Cisco Web Security Appliance HTTP Length Denial of Service Vulnerability

[Cisco Systems Product Security Incident Response Team <psirt () cisco com>]

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Cisco Web Security Appliance HTTP Length Denial of Service Vulnerability

Advisory ID: cisco-sa-20160518-wsa3

Revision 1.0

For Public Release 2016 May 18 16:00 UTC (GMT)

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Summary
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A vulnerability in HTTP request parsing in Cisco AsyncOS for the Cisco Web Security Appliance (WSA) could allow an 
unauthenticated, remote attacker to cause a denial of service (DoS) condition when the proxy process unexpectedly 
restarts.

The vulnerability occurs because the affected software does not properly allocate space for the HTTP header and any 
expected HTTP payload. 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 when the proxy process unexpectedly reloads, which 
can cause traffic to be dropped.

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:

 http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20160518-wsa3

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