Some vulnerabilities have been discovered in the Sage extension for Firefox, which can be exploited by malicious people to conduct script insertion attacks.

The vulnerabilities are caused due to some input validation errors in the processing of the content tag in RSS feeds and certain tags in Atom feeds. This can e.g. be exploited to inject and execute arbitrary HTML and script code in a local context by tricking a user into adding a malicious RSS feed and then viewing the content of it.

Successful exploitation of certain tags in Atom feeds may require that the "Allow HTML tags" setting is enabled (enabled by default).

The vulnerabilities have been confirmed in version 1.3.6. Other versions may also be affected.

Solution
Update to version 1.3.7.

Provided and/or discovered by
pdp and Kevin Hamilton.

Changelog
Further details available to Secunia VIM customers

Original Advisory
http://www.gnucitizen.org/blog/cross-context-scripting-with-sage
http://mozdev.org/bugs/show_bug.cgi?id=15101

Deep Links
Links available to Secunia VIM customers