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CVE-2011-4367: Apache MyFaces information disclosure vulnerability

Severity: Important

Vendor: The Apache Software Foundation

Versions Affected:
            MyFaces Core 2.0.1 to 2.0.11
            MyFaces Core 2.1.0 to 2.1.5
            Earlier versions are not affected

Description:

MyFaces JavaServer Faces (JSF) allows relative paths in the
javax.faces.resource 'ln' parameter or writing the url so the resource
name include '..' sequences . An attacker could use the security
vulnerability to view files that they should not be able to.

Mitigation:

Users of affected versions should apply one of the following mitigations:
MyFaces Core 2.0.x users should update to 2.0.12
MyFaces Core 2.1.x users should update to 2.1.6

Example:

In linux or similar systems:

http://<hostname>:<port>/<context-root>/faces/javax.faces.resource/web.xml?ln=../WEB-INF
http://<hostname>:<port>/<context-root>/faces/javax.faces.resource/../WEB-INF/web.xml

or in windows systems:

http://<hostname>:<port>/<context-root>/faces/javax.faces.resource/web.xml?ln=..\\WEB-INF
http://<hostname>:<port>/<context-root>/faces/javax.faces.resource/..\\WEB-INF/web.xml

The 'ln' parameter should not allow a relative path. In the above example
the contents of the web.xml are displayed in the response to the attacker.
The part of the url that derive the resource name should not allow '..' as
valid char sequence.

Credit: Issue reported by Paul Nicolucci thanks to the security team at IBM

References:

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regards,

Leonardo Uribe