Exaprobe
www.exaprobe.com
Security Advisory
Advisory Name: Multiple vulnerabilities in w3who
Release Date: 6 December 2004
Application: Microsoft ISAPI extension w3who.dll
Platform: Windows 2000/XP Resource Kit
Severity: Remote code execution
Author: Nicolas Gregoire <[email protected]>
Vendor Status: Affected code is no more available
CVE Candidates: CAN-2004-1133 and CAN-2004-1135
Reference: www.exaprobe.com/labs/advisories/esa-2004-1206.html
>From the Windows 2000 Resource Kit documentation :
"W3Who is an Internet Server Application Programming Interface
(ISAPI) application dynamic-link library (DLL) that works within
a Web page to display information about the calling context of
the client browser and the configuration of the host server."
There're two basic XSS vulnerabilities, and an easily exploitable
buffer-overflow.
XSS vulnerability when displaying HTTP headers :
Connection: keep-alive<script>alert("Hello")</script>
XSS vulnerability in error message :
/scripts/w3who.dll?bogus=<script>alert("Hello")</script>
Buffer overflow when called with long parameters :
/scripts/w3who.dll?AAAAAAAAA…[519 to 12571]…AAAAAAAAAAAAA
After notification by Exaprobe, Microsoft choosed to remove
the web download of this component and do not have any plans
to issue an updated version.
Restrict access to the DLL.
Do not use it on production servers.
Thanks to HD Moore, a Metasploit plugin will be integrated in the
upcoming release of the Metasploit Framework.
A NASL script has been sent to Nessus developpers.
The Common Vulnerabilities and Exposures (CVE) project has assigned
the following names to these issues. These are candidates for
inclusion in the CVE list (http://cve.mitre.org), which standardizes
names for security problems.
CAN-2004-1133 Cross-site scripting issues in w3who.dll
CAN-2004-1134 Buffer-overflow in w3who.dll
–
Nicolas Gregoire ----- Consultant en Sécurité des Systèmes d'Information
[email protected] ------[ ExaProbe ]------ http://www.exaprobe.com/
PGP KeyID:CA61B44F FingerPrint:1CC647FF1A55664BA2D2AFDACA6A21DACA61B44F
Full-Disclosure - We believe in it.
Charter: http://lists.netsys.com/full-disclosure-charter.html