Kunena forum extension for Joomla multiple reflected cross-site scripting vulnerabilities

Class:      Input Validation Error
CVE      N/A
Remote      Yes
Local      No
Published    02/07/2014

Credit      Raymond Rizk of Dionach (vulns@dionach.com)
Vendor      Kunena
Vulnerable    Kunena v3.0.5
Solution Status:  Fixed by Vendor

Kunena Forum is prone to multiple reflected cross-site scripting vulnerabilities because it fails to sufficiently sanitize user-supplied data.

An attacker may leverage these issues to execute arbitrary script code in the browser of an unsuspecting user in the context of the affected site, steal cookie-based authentication credentials, and obtain sensitive information.

Kunena v3.0.5 is known to be vulnerable. Earlier versions may also be vulnerable.

To exploit this issue, an attacker must have a user account on the forum. The vulnerability affects all pages/tasks that use parameters in the form of “parameter[]”. Additionally, the file upload and profile image upload functionality are also vulnerable. This can be seen in the proof of concept example below:

POST /index.php?option=com_kunena&view=home&defaultmenu=130&Itemid=12
Content-Disposition: form-data; name="avatarfile"; filename="<iframe src=javascript:alert('XSS')>"

Vendor informed and a new version (3.0.6) was released on 28/07/2014. Vendor recommends updating Kunena to the latest version.