Charles McAuley has discovered a vulnerability in Firefox, which can be exploited by malicious people to trick users into disclosing sensitive information.

The vulnerability is caused due to a design error where a script can cancel certain keystroke events when entering text. This can be exploited to trick a user into typing a filename in a file upload input field by changing focus and canceling the "OnKeyPress" JavaScript event on certain characters.

Successful exploitation allows an arbitrary file on the user's system to be uploaded to a malicious web site, but requires that the user type text containing the characters of the filename.

The vulnerability is confirmed in version 1.5.0.4 and 2.0.0.1. Other versions may also be affected.

Solution
Update to version 2.0.0.8.

Provided and/or discovered by
Charles McAuley

Additional Information:
Michal Zalewski

NOTE: A variant of this vulnerability was reported in a Mozilla Bugzilla bug entry back in 2000.

Changelog
Further details available to Secunia VIM customers

Original Advisory
Mozilla Foundation:
http://www.mozilla.org/security/announce/2007/mfsa2007-32.html

Charles McAuley:
http://lists.grok.org.uk/pipermail/full-disclosure/2006-June/046610.html

Other references
Further details available to Secunia VIM customers

Deep Links
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