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  Core Security Technologies - CoreLabs Advisory
       http://corelabs.coresecurity.com/

  IBM WebSphere Application Server Cross-Site Request Forgery


1. *Advisory Information*

Title: IBM WebSphere Application Server Cross-Site Request Forgery
Advisory ID: CORE-2010-1021
Advisory URL: http://www.coresecurity.com/content/IBM-WebSphere-CSRF
Date published: 2011-06-15
Date of last update: 2011-06-15
Vendors contacted: IBM
Release mode: User release


2. *Vulnerability Information*

Class: Cross-Site Request Forgery (CSRF) [CWE-352]
Impact: Code execution
Remotely Exploitable: Yes
Locally Exploitable: No
CVE Name: CVE-2010-3271


3. *Vulnerability Description*

WebSphere is IBM's integration software platform. It includes the entire
middleware infrastructure --such as servers, services, and tools--
needed to write, run, and monitor 24x7 industrial-strength, on demand
Web applications and cross-platform, cross-product solutions. WebSphere
Application Server is the base for the infrastructure; everything else
runs on top of it [1].

The administrative console of IBM WebSphere Application Server is
vulnerable to Cross-Site Request Forgery (CSRF) attacks, which can be
exploited by remote attackers to force a logged-in administrator to
perform unwanted actions on the IBM WebSphere administrative console, by
enticing him to visit a malicious web page.


4. *Vulnerable packages*

   . IBM WebSphere Application Server 7.0.0.11
   . IBM WebSphere Application Server 7.0.0.13
   . Older versions are probably affected too, but they were not checked.


5. *Non-vulnerable packages*

Contact the vendor for a fix.


6. *Vendor Information, Solutions and Workarounds*

Contact the vendor for a fix. The following are workarounds for this issue.

6.1. *Server side*

According to OWASP [2], CSRF vulnerabilities can be avoided by checking
the referrer of the HTTP request and verifying that the request comes
from the original site. A potential workaround is thus to set a rule on
a Web Application Firewall that checks the referrer of the requests, and
verifies that all the requests to the WebSphere administrative console
are originated from the same site.

6.2. *Client side*

An administrator of WebSphere administrative console could mitigate the
bug by using Firefox and the NoScript add-on; more precisely by making
use of the ABE [3] (Application Boundaries Enforcer) feature of
NoScript. With ABE it is possible to define rules such as the following:

/-----
Site *.example.com
Accept from SELF
Deny
- -----/

This rule applies to *.example.com; it will allow all the requests made
from the same site, and block all the requests directed to *.example.com
but generated from any other site, avoiding that Firefox sends the
request to the server. The syntax of the ABE rules is defined here:
http://noscript.net/abe/abe_rules.pdf


7. *Credits*

This vulnerability was discovered and researched by Francisco Falcon
from Core Security Technologies during Bugweek 2010 [4]. Additional
research was performed by Alejandro Rodriguez. Publication was
coordinated by Carlos Sarraute.


8. *Technical Description / Proof of Concept Code*

The administrative console (also known as Integrated Solutions Console)
of IBM WebSphere Application Server is vulnerable to Cross-Site Request
Forgery (CSRF) [2] attacks, which can be exploited by remote attackers
to force a logged-in administrator to perform unwanted actions on the
IBM WebSphere administrative console, by enticing him to visit a
malicious web page.

The administrative console of IBM WebSphere Application Server includes
a standard protection mechanism against Cross-Site Request Forgery,
which consists of a token that is included as a hidden field on every
'FORM', named 'csrfid', that is sent to the web server in each 'POST'
request performed by the web browser. When the web server receives a
'POST' request, it checks that the 'csrfid' token included in the
parameters of the 'POST' request matches the anti-CSRF token associated
with the current session. If they do not match, then IBM WebSphere
responds with an "'Unauthorized Request'" message, thus effectively
preventing CSRF.

However, in certain areas of the administrative console, WebSphere
forgets to check the value of the 'csrfid' token when processing 'POST'
requests, even though the 'csrfid' hidden field is included in every
'FORM', making the application vulnerable to Cross-Site Request Forgery.

The vulnerable areas of the WebSphere administrative console include the
'Security > Global Security' panel [6], and the 'Save changes to the
master configuration' feature. This makes possible for a remote attacker
to disable the 'Administrative Security', 'Application Security' and
'Java 2 Security' options, and then to save the changes to the
configuration, by tricking an IBM WebSphere administrator which is
currently logged in to the administrative console to visit a malicious
web page. Also note that IBM WebSphere 7.0 with Fix Pack 11 did not
include a 'csrfid' token for the 'Save changes to the master
configuration' feature; Fix Pack 13 introduced it, but anyways it is
ignored on the server side when processing a request to save the master
configuration.

The following HTML code is a Proof-of-Concept of a specially crafted web
page that will leverage the CSRF vulnerability in order to disable the
'Administrative Security', 'Application Security' and 'Java 2 Security'
options, if a logged-in administrator visits it:

/-----
<html>
<body>
<iframe id="iframe1" style="visibility:hidden"></iframe>
<iframe id="iframe2" style="visibility:hidden"></iframe>
  <script>
    //The first request disables "Administrative security" and
"Application security" options
    document.getElementById("iframe1").src =
"https://<ip>:9043/ibm/console/adminSecurityDetail.do?action=Edit&displayActiveUserRegistry=Repositorios+federados&selectUserRegistry=WIM&activeAuthMechanism=LTPA&apply=Aplicar";

    //The second request saves the changes in the WebSphere configuration
    document.getElementById("iframe2").src =
"https://<ip>:9043/ibm/console/syncworkspace.do?saveaction=save&directsave=true";
  </script>
</iframe>
</body>
</html>

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9. *Report Timeline*

. 2010-11-24:
Core Security Technologies contacts IBM, requesting the proper point of
contact to report a security vulnerability in IBM WebSphere Application
Server.

. 2010-11-29:
Vendor responds providing the point of contact to report the
vulnerability, and its PGP key to encrypt communications.

. 2010-12-14:
Core sends an advisory draft, containing the technical details needed to
reproduce the vulnerability. Publication of Core's advisory is
temporarily set to January 10, 2011.

. 2010-12-14:
IBM acknowledges the receipt of the technical information.

. 2010-12-21:
Core asks the vendor whether it was able to reproduce the vulnerability.

. 2011-01-05:
Vendor responds that it was able to reproduce the issue and confirms
there is a vulnerability. Vendor informs Core that it is still working
through the total products affected, that it is multiple products, and
that this vulnerability is creating real issues on being able to resolve
it. Vendor requests Core an extension on the release date while it
completes the full evaluation of risk assessment and remedy production.
Vendor expects to have that information in the following 2 weeks.

. 2011-01-06:
Core responds that it is willing to postpone the publication of its
advisory. However to take that decision more information about the
vendor's analysis of the vulnerability and its plans for developing a
fix is required. In particular, Core requests a list of all affected
products and versions, and also some insight on the difficulties of
fixing this issue. In the meantime, the publication of this advisory is
rescheduled to February 15th, 2011. (No reply received.)

. 2011-01-31:
Since more than 3 weeks have passed since the last communication, Core
requests an update on this issue. In particular Core requests to receive
information respect to:

   . the vendor's analysis of the vulnerability,
   . the vendor's plans for developing a fix,
   . a list of affected products and versions.

. 2011-02-01:
Core reminds the vendor that in case of not receiving an answer, it will
publish its advisory as "user release" on the scheduled date (February
15th, 2011).

. 2011-02-01:
Vendor replies that it has asked a status update from the WebSphere team
to convey to Core, and will provide it briefly.

. 2011-02-08:
Core requests an update on this issue.

. 2011-02-14:
Core reminds the vendor that the advisory is scheduled to be published
on February 15th. Core communicates its willingness to publish the
advisory as "coordinated release" based on concrete feedback from the
vendor.

. 2011-02-14:
Vendor communicates Core that it is working on a statement to provide
for Core, and that since the PSIRT is a new mechanism within IBM, it is
still defining the way to provide consistent statements. In the
meantime, the vendor informs that:

   . The vendor has a potential solution designed and partially
implemented to fully secure the console. It is in the process of
reviewing the design and the impact to stack products.
   . There are an unknown number of stack products affected. WebSphere
Application Server (WAS) stack products that use the ISC (Integrated
Solutions Console) based console are affected. The vendor is still
gathering the list of products affected, and must determine the impact
of implementing the fix.
   . There is a meeting planned to decide on the final solution to be
implemented and determine the key delivery dates. These decisions will
be taken in mid March or later.
   . The target dates for release reach into Q3 2011.

. 2011-02-17:
Core replies that it has rescheduled publication of its advisory (for
the second time) to March 21, 2011, in order to give PSIRT more time to
come up with concrete responses to the requested information. Core
provides additional information about its own publication process [5].
Without additional information, it is difficult for Core to understand
the reason why users of vulnerable WebSphere software should remain
without any solution until Q3 2011.

. 2011-03-17:
After 1 month of silence, the vendor informs Core that IBM's point of
contact for this issue has changed, and that further communications will
be handled by the head of IBM's Secure By Design initiative which
includes the IBM PSIRT.

. 2011-03-17:
Vendor requests Core to postpone the publication of its advisory until
early October 2011.

. 2011-03-18:
Vendor communicates that since Core hasn't responded to the request
(sent the previous day) of deferring the public disclosure of this
security vulnerability from 21 March to early October 2011, IBM
considers that Core agrees.

. 2011-03-21:
Core answers that October 2011 is well beyond what it considers a
reasonable timeframe to patch the type of bug that it has reported (a
Cross-Site Request Forgery). Additionally the vendor didn't provide Core
a technical analysis of the bug, explaining the difficulty to patch it
(and why it would take IBM around 10 months to release fixes). The
vendor didn't provide either the requested list of affected products and
versions. According to Core's publication policy, the decision of
postponing the publication of an advisory cannot be taken without
technical arguments that justify that decision. This is why Core cannot
agree with IBM's request to postpone publication until October 2011,
unless the requested technical information is provided by the vendor.
(No reply received.)

. 2011-04-25:
Core communicates the vendor that it has rescheduled the publication of
its advisory to June 14th, 2011. That date corresponds to a 6 month
timeframe after technical details about this vulnerability were sent to
IBM (on December 14th, 2010), and is considered final. (No reply received.)

. 2011-06-15:
The advisory CORE-2010-1021 is published.


10. *References*

[1] IBM WebSphere Application Server:
http://www-01.ibm.com/software/webservers/appserv/was/

[2] Cross-Site Request Forgery (CSRF)
http://www.owasp.org/index.php/Cross-Site_Request_Forgery_%28CSRF%29

[3] Application Boundaries Enforcer (ABE)
http://noscript.net/abe/

[4] The author participated in Core Security's Bugweek 2010 as member of
the team "Ex Tester fuErTes and Exploit Testers".

[5] Finding bugs and publishing advisories _ the Core Security way
http://corelabs.coresecurity.com/index.php?module=Wiki&action=view&type=publication&name=Finding_bugs_and_publishing_advisories

[6] IBM WebSphere Reference, Global Security settings:
http://publib.boulder.ibm.com/infocenter/wasinfo/fep/topic/com.ibm.websphere.nd.multiplatform.doc/info/ae/ae/usec_secureadminappinfra.html


11. *About CoreLabs*

CoreLabs, the research center of Core Security Technologies, is charged
with anticipating the future needs and requirements for information
security technologies. We conduct our research in several important
areas of computer security including system vulnerabilities, cyber
attack planning and simulation, source code auditing, and cryptography.
Our results include problem formalization, identification of
vulnerabilities, novel solutions and prototypes for new technologies.
CoreLabs regularly publishes security advisories, technical papers,
project information and shared software tools for public use at:
http://corelabs.coresecurity.com.


12. *About Core Security Technologies*

Core Security Technologies enables organizations to get ahead of threats
with security test and measurement solutions that continuously identify
and demonstrate real-world exposures to their most critical assets. Our
customers can gain real visibility into their security standing, real
validation of their security controls, and real metrics to more
effectively secure their organizations.

Core Security's software solutions build on over a decade of trusted
research and leading-edge threat expertise from the company's Security
Consulting Services, CoreLabs and Engineering groups. Core Security
Technologies can be reached at +1 (617) 399-6980 or on the Web at:
http://www.coresecurity.com.


13. *Disclaimer*

The contents of this advisory are copyright (c) 2011 Core Security
Technologies and (c) 2011 CoreLabs, and are licensed under a Creative
Commons Attribution Non-Commercial Share-Alike 3.0 (United States)
License: http://creativecommons.org/licenses/by-nc-sa/3.0/us/


14. *PGP/GPG Keys*

This advisory has been signed with the GPG key of Core Security
Technologies advisories team, which is available for download at
http://www.coresecurity.com/files/attachments/core_security_advisories.asc.
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