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CERT Coordination Center

The Wizz RSS Reader chrome access vulnerability

Vulnerability Note VU#319464

Original Release Date: 2007-04-16 | Last Revised: 2007-04-17


The Wizz RSS Reader contains a vulnerability that may allow an attacker to take any action that Mozlla Firefox can.


The Mozilla Firefox user interface components outside of the content area are created using chrome. This includes toolbars, menu bars, progress bars, and window title bars. Chrome provides content, locale, and skin information for the user interface. The Wizz RSS reader is an extension to Mozilla Firefox that searches and displays RSS feeds.

The Wizz RSS Reader reader contains a vulnerability. This vulnerability occurs because The Wizz allows javascript in an RSS feed's DOM to be executed in the context of the Wizz RSS Reader's chrome window.

Note that to exploit this vulnerability an attacker would have to convince a user to load a specially crafted RSS feed using The Wizz.


A remote unauthenticated attacker may be able to take any action that Mozilla Firefox is capable of performing. This includes downloading arbitrary files, redirecting browser requests, and access stored passwords.


Version 2.1.9 of the Wizz RSS reader has been released to address this vulnerability. Users are encouraged to update to version 2.1.9 as soon as possible.

Vendor Information


Wizz Computers Affected

Notified:  March 23, 2007 Updated: April 16, 2007



Vendor Statement

Description of Problem:

Wizz RSS News Reader version 2.1.7 (Including earlier versions) is vulnerable to cross-site scripting (XSS) exploits. A "quick fix" was applied to version 2.
1.8, but the fix was found to be very weak and, in most cases, ineffectual. The vulnerability allowed non-trusted scripts, injected into various RSS and Atom
feeds, to execute within the trusted chrome space of the Firefox web browser.

Problem Resolution:

Wizz RSS News Reader version 2.1.9 includes a fix for the above mentioned cross-site scripting vulnerability. In version 2.1.9, all feeds are "sanitized" as
they are parsed.

It is very highly recommended that ALL users of Wizz RSS News Reader upgrade to version 2.1.9, as soon as they possibly can.

Version 2.1.9 can be installed from


Many thanks to Jefferson Ogata of NOAA Computer Incident Response Team (N-CIRT) for his invaluable input with regard to reporting and evaluating the vulnerability. Also, many thanks to Jefferson Ogata for his valued advice on fixing the vulnerability, and for the time taken to produce proof of concept code.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

CVSS Metrics

Group Score Vector
Base 0 AV:--/AC:--/Au:--/C:--/I:--/A:--
Temporal 0 E:ND/RL:ND/RC:ND
Environmental 0 CDP:ND/TD:ND/CR:ND/IR:ND/AR:ND



Thanks to the N-CIRT Lab for reporting this vulnerability.

This document was written by Ryan Giobbi.

Other Information

CVE IDs: None
Severity Metric: 3.27
Date Public: 2007-04-13
Date First Published: 2007-04-16
Date Last Updated: 2007-04-17 13:49 UTC
Document Revision: 23

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