[SA23669] Movable Type "nofollow" Plugin Comment Script Insertion

Type securityvulns
Reporter Securityvulns
Modified 2007-01-12T00:00:00


TITLE: Movable Type "nofollow" Plugin Comment Script Insertion


VERIFY ADVISORY: http://secunia.com/advisories/23669/

CRITICAL: Less critical

IMPACT: Cross Site Scripting

WHERE: >From remote

SOFTWARE: Movable Type 3.x http://secunia.com/product/5753/

DESCRIPTION: A vulnerability has been discovered in Movable Type, which can be exploited by malicious people to conduct cross-site scripting attacks.

Input passed in the "Comments" form field when posting comments to blog entries is not properly sanitised before being stored. This can be exploited to insert arbitrary HTML and script code, which is then executed in a user's browser session in context of an affected site when the comment is viewed.

Successful exploitation requires that the "nofollow" plugin is disabled, which is not its default state, and that "Immediately publish comments from" is set to a value such that the comment does not require moderation.

The vulnerability is confirmed in version 3.33. Other versions may also be affected.

SOLUTION: Enable the "nofollow" plugin.

Fixed in version 3.34b1.

PROVIDED AND/OR DISCOVERED BY: Mike Stay, Jacques Distler and Zack Ajmal

ORIGINAL ADVISORY: Jacques Distler: http://golem.ph.utexas.edu/~distler/blog/archives/001102.html

Zack Ajmal: http://www.zackvision.com/weblog/2007/01/movabletype-security-bug.html

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