Patrick Webster has reported a vulnerability in MySource, which can be exploited by malicious people to bypass certain security restrictions and conduct cross-site scripting attacks.

It is possible to include the contents of arbitrary web pages by passing "fetch_url" to the "sq_remote_page_action" parameter and the URL of the web page to include to the "sq_remote_page_url" parameter (or in newer versions by passing a base64 encoded URL to the "sq_content_src" parameter). This can be exploited to execute arbitrary HTML and script code in a user's browser session in context of an affected site or to abuse an affected site as an HTTP proxy to e.g. bypass certain security restrictions.

The vulnerability is reported in MySource Matrix 3.8 and MySource 2.x. Other versions may also be affected.

Solution
Newer versions offer a whitelist functionality to restrict inclusion to trusted sites only.

Provided and/or discovered by
Patrick Webster

Changelog
Further details available in Customer Area

Original Advisory
http://users.tpg.com.au/adsl2dvp/advisories/200607-mysourcematrix.txt

Deep Links
Links available in Customer Area