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:  
CVE number: -  
impact: Medium  
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  
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."  
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  
- 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:  
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  
Step 2: Transpose the POST parameters into GET parameters and  
build a new URL with it.  
Step 3: Strip out the javax.faces.ViewState GET parameter from the URL.  
Step 4: Prefix the javax.faces.ClientWindow GET parameter with  
the following PoC payload:  
Resulting URL:  
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:  
2018-11-22: Contacting vendor through  
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  
2019-06-13: Contacting vendor through  
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  
Oracle has addressed the reported issue for the versions 2.2 and 2.3:  
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.  
Advisory URL:  
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EOF Jean-Benjamin Rousseau - Guillaume Crouquet / @2019