CSNC-2016-001 - XSS in OpenAM

############################################################
#
#
# COMPASS SECURITY ADVISORY http://www.csnc.ch/en/downloads/advisories.html
#############################################################
#
# CSNC ID:          CSNC-2016-001
# Product:          OpenAM [1]
# Vendor:           ForgeRock
# Subject:           Cross-Site Scripting - XSS
# Risk:                  High
# Effect:              Remotely exploitable
# Author:            Stephan Sekula (stephan.sekula@csnc.de)
# Date:                 February 23rd 2016
#
#############################################################


Introduction:
-------------
OpenAM provides core identity services to simplify the implementation of
transparent single sign-on (SSO) as a security component in a network
infrastructure. OpenAM provides the foundation for integrating diverse
web applications that might typically operate against a disparate set of
identity repositories and are hosted on a variety of platforms such as
web and application servers. [1]

Compass Security discovered a web application security flaw in the OpenAM
application which allows an attacker to manipulate the resulting website.
This allows, for instance, stealing of user sessions, attacking the user's
browser or redirecting the user to a Phishing website. Since it is the
victim who needs to visit the malicious link, this attack is possible for
unauthenticated attackers who do not have access to the affected websites.


Affected Versions:
------------------
The following OpenAM versions are vulnerable:
- 9-9.5.5
- 10.0.0-10.0.2
- 10.1.0-Xpress
- 11.0.0-11.0.3
- 12.0.0-12.0.2

OpenAM version 13.0.0 is not vulnerable.


Patches:
--------
OpenAM released patches for each affected version as part of OpenAM
Security Advisory #201601 [2].


Technical Description:
----------------------
OpenAM provides a blacklist mechanism that allows specifying dangerous
input. If user input is part of this blacklist, the user should be
redirected to an error page. However, this mechanism is not implemented
in page exportmetadata.jsp. Exploiting the vulnerability will lead to
so-called Cross-Site Scripting (XSS), allowing the execution of
JavaScript in the context of the victim and thus the impersonation of
logged-in OpenAM users:
https://<URL>/.../exportmetadata.jsp?entityid=sp&realm="<script>alert(0)</script>

Response:
ERROR : Unable to read configuration of component "SAML2" for realm
""<script>alert(0)</script>".

Furthermore, a blacklist approach bears the risk of missing malicious input.


Milestones:
-----------
2015-12-16: Vulnerability discovered
2016-01-04: Vendor notified
2016-02-05: Vendor provided patched version
2016-02-23: Public disclosure


References:
-----------
[1] http://openam.forgerock.org/
[2] https://forgerock.org/2016/02/openam-security-advisory-201601/