XPath Injection

SEC Consult Vulnerability Lab Security Advisory < 20131227-0 >

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title: XPath Injection

product: IBM Web Content Manager (WCM)

vulnerable version: 6.x, 7.x, 8.x

fixed version: -

impact: high

homepage: www.ibm.com

found: 2013-10-27

CVE: CVE-2013-6735

by: A.Antukh, S.Temnikov

SEC Consult Vulnerability Lab

www.sec-consult.com

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Vendor description:

-------------------

"IBM® Web Content Manager is designed to accelerate web content development and

deployment through Internet, intranet and extranet sites. This software enables

users to create and publish content while IT retains control. Through advanced

personalization, IBM Web Content Manager delivers the right information to the

right audience when needed, providing an exceptional customer experience"

Source: www-03.ibm.com/software/products/en/ibmwebcontmana

 

Business recommendation:

------------------------

The discovered vulnerability can be exploited _without_ authentication and

therefore pose a high security risk - it allows extraction of configuration

data from the server. The impact of the XPath vulnerability isn't researched

fully. SEC Consult suspects that it is possible to extract sensitive

information that will be useful for further attacks. The recommendation of SEC

Consult is to immediately install patches provided by the vendor.

 

Vulnerability overview/description:

-----------------------------------

A typical URL for a host with installed WCM looks like this:

[HOST]:[PORT]/wps/wcm/connect/[PATH]

The "connect" servlet provided in the standard installation of IBM Web Content

Manager parses the PATH element as follows:

[PATH] = [LIBRARY]/[SITE_AREA_PATH]/[CONTENT]

Due to insufficient validation, the "LIBRARY" element suffers from an

XPath-injection vulnerability.

An unauthenticated user is able to perform blind XPath Injection attacks e.g.

get current application configuration, enumerate nodes and extract other

valuable information from vulnerable installations of Web Content Manager.

 

Proof of concept:

-----------------

The vulnerability is exploited due to improper validation of the LIBRARY

parameter, which is parsed by the "connect" servlet.

The most basic cases are presented below, and allow an attacker to manipulate

logic of the request. The "false" clause causes an error, the "true" clause (if

not defined explicitly) redirects an attacker to the

"/wcm/webinterface/login/login.jsp" page.

True clause: [HOST]:[PORT]/wps/wcm/connect/' or 'a'='a

False clause: [HOST]:[PORT]/wps/wcm/connect/' or 'a'='b

Knowing the difference between responses of the true and false clauses, it is

possible to manipulate requests in order to extract the information. For

example, if the following request returns TRUE, this would give an attacker

information about the "name" property.

[HOST]:[PORT]/wps/wcm/connect/' or (@ibmcontentwcm:name = "pznDT") or 'a'='b

In a similar way, with use of the "jcr:like" and "jcr:contains" functions one

can effectively restore the value for the "target" property.

 

Vulnerable / tested versions:

-----------------------------

The vulnerability is verified to exist in the 7.0 and 8.0 versions of WCM which

are the most recent versions at the moment of writing the advisory.

 

Vendor contact timeline:

------------------------

2013-12-04: Contacted vendor through psirt@vnet.ibm.com.

2013-12-04: Initial vendor response.

2013-12-06: Issues will be verified.

2013-12-20: Security bulletin released.

2013-12-27: SEC Consult releases coordinated security advisory.

 

Solution:

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Apply the Interim Fix PI07777

www.ibm.com/eserver/support/fixes/fixcentral/swg/quickorder?productid=WebSphere%20Portal&brandid=5&apar=PI07777

 

Workaround:

-----------

No workaround available.

 

Advisory URL:

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www.sec-consult.com/en/Vulnerability-Lab/Advisories.htm

 

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

SEC Consult Vulnerability Lab

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EOF A. Antukh / @2013