TITLE:
Cisco CSS SSL Client Certificate Handling Denial of Service

SECUNIA ADVISORY ID:
SA17260

VERIFY ADVISORY:
http://secunia.com/advisories/17260/

CRITICAL:
Moderately critical

IMPACT:
DoS

WHERE:
>From remote

OPERATING SYSTEM:
Cisco Content Services Switch 11500 Series
http://secunia.com/product/5680/

DESCRIPTION:
A vulnerability has been reported in Cisco 11500 CSS (Content
Services Switch), which can be exploited by malicious people to cause
a DoS (Denial of Service).

The vulnerability is caused due to a memory corruption error when
processing malformed client certificate during SSL session
negotiation.  This can be exploited to cause the CSS to reload via a
specially crafted client certificate even when the CSS did not
request for a client certificate during SSL session negotiation.

Successful exploitation requires that CSS is configured to provide
SSL termination services.

The vulnerability has been reported in 11500 Series CSS running
version 7.1 through 7.5 of the Cisco WebNS operating system.

SOLUTION:
Fixes are available (see patch matrix in vendor advisory).
http://www.cisco.com/en/US/products/products_security_advisory09186a008054bc9b.shtml#software

PROVIDED AND/OR DISCOVERED BY:
Reported by vendor.

ORIGINAL ADVISORY:
http://www.cisco.com/warp/public/707/cisco-sa-20051019-css.shtml

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