Secunia

Paul Szabo has discovered a security issue in Firefox, which can be exploited by malicious people to conduct cross-site scripting attacks.

The security issue is caused due to embedded iframes inheriting the charset of parent frames when the charset is set manually. This can be exploited to execute arbitrary HTML and script code in a user's browser session in context of certain sites that are included via iframes in a malicious page.

Successful exploitation requires that the target user is tricked into changing the charset of the parent page e.g. to UTF-7.

The security issue is confirmed in Firefox 2.0.0.11. Other versions may also be affected.

Solution
Do not change the character encoding manually. Do not browse untrusted sites.

Provided and/or discovered by
Paul Szabo

Original Advisory
http://lists.grok.org.uk/pipermail/full-disclosure/2007-December/058752.html

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