TITLE:
YaBB Attachment Script Insertion Vulnerability

SECUNIA ADVISORY ID:
SA17411

VERIFY ADVISORY:
http://secunia.com/advisories/17411/

CRITICAL:
Moderately critical

IMPACT:
Unknown, Cross Site Scripting

WHERE:
>From remote

SOFTWARE:
YaBB 2.x
http://secunia.com/product/6070/

DESCRIPTION:
A vulnerability has been discovered in YaBB, which can be exploited
by malicious people to conduct script insertion attacks.

The vulnerability is caused due to an input validation error in the
attachment upload handling. This can be exploited to execute
arbitrary HTML and script code in a user's browser session in context
of an affected site by attaching a malicious HTML document with a
valid file extension (e.g. ".gif") in a post.

Successful exploitation requires that the attachment is accessed
directly in the Microsoft Internet Explorer browser (e.g. by opening
an attachment in a post).

Some other issues which may be security related have also been
reported.

The vulnerability has been confirmed in version 2.0. Prior versions
may also be affected.

SOLUTION:
Update to version 2.1.
http://www.yabbforum.com/downloads.php

PROVIDED AND/OR DISCOVERED BY:
Reported by vendor.

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