Cisco Security Advisory: Cisco Web Security Appliance Cached Range Request Denial of Service Vulnerability

[Cisco Systems Product Security Incident Response Team <psirt@xxxxxxxxx>]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Cisco Web Security Appliance Cached Range Request Denial of Service 
Vulnerability

Advisory ID: cisco-sa-20160518-wsa2

Revision 1.0

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

+---------------------------------------------------------------------

Summary
=======

A vulnerability in the cached file-range request functionality of Cisco AsyncOS 
for Cisco Web Security Appliance (WSA) could allow an unauthenticated, remote 
attacker to cause a denial of service (DoS) condition on an appliance due to 
the appliance running out of system memory.

The vulnerability is due to a failure to free memory when a file range for 
cached content is requested through the WSA. An attacker could exploit this 
vulnerability by opening multiple connections that request file ranges through 
the affected device. A successful exploit could allow the attacker to cause the 
WSA to stop passing traffic when enough memory is used and not freed.

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

 
http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20160518-wsa2

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.5 (SunOS)
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=XrBA
-----END PGP SIGNATURE-----