(The following advisory is also available in PDF format for download at:
http://www.cybsec.com/vuln/CYBSEC_Security_Advisory_AppScanQA_RemoteCodeExec.pdf)


CYBSEC S.A.
www.cybsec.com

Advisory Name: Watchfire AppScan QA Remote Code Execution
==========

Vulnerability Class: Buffer Overflow
=============

Release Date: 12/15/2005
=========

Affected Applications:
==============
* AppScan QA  5.0.609 / Subscription 7
* AppScan QA  5.0.134

Affected Platforms:
=============
* Platform-Independent: Tested on Windows 2000 Server SP4

Local / Remote: Remote
==========

Severity: High
======

Author:  Mariano Nuñez Di Croce
=====

Vendor Status:
==========
* Confirmed, update released.

Reference to Vulnerability Disclosure Policy:
=============================
http://www.cybsec.com/vulnerability_policy.pdf

Product Overview:
============
AppScan QA is an automated web application testing tool that provides QA
personnel with security defect analysis and remediation information.
Instead of manually searching for security defects, application testers
trust AppScan QA to detect security defects and vulnerabilities
automatically as an integrated component of enterprise development and
testing processes. AppScan QA automates test script creation,
modification, and maintenance to ensure reliable and repeatable testing.

Vulnerability Description:
=================
The vulnerability specifically exists in the way AppScan QA processes
401 HTTP responses. If a custom 401 response is specially crafted,
containing a WWW-Authenticate header with the Realm field consisting of
more than 351 characters, a buffer overflow occurs, leading to remote
code execution with the privileges of the user running AppScan QA.

Proof Of Concept:
============
A Proof of Concept can be found at
http://www.cybsec.com/vuln/AppScanQA-RemoteCodeExec-PoC.zip

Mitigating Factors:
============
For the exploit to succeed, an AppScan QA user must analyze a web server
specially configured to exploit the vulnerability.

Solutions:
=======
Users should upgrade AppScan QA to Subscription 8, using the AppScan
Update Tool.

Vendor Response:
============
* 10/12/2005: Initial Vendor Contact.
* 10/18/2005: Vendor Confirmed Vulnerability.
* 11/02/2005: Vendor Releases Update.
* 12/15/2005: Advisory Public Disclosure.

Contact Information:
==============
For more information regarding the vulnerability feel free to contact
the author at mnunez {at} cybsec.com.

For more information regarding CYBSEC: www.cybsec.com
(c) 2005 - CYBSEC S.A. Security Systems