HTB22867: XSS in PhotoSmash wordpress plugin

Vulnerability ID: HTB22867
Reference: http://www.htbridge.ch/advisory/xss_in_photosmash_wordpress_plugin.html
Product: PhotoSmash wordpress plugin
Vendor: Byron Bennett ( http://smashly.net/ )
Vulnerable Version: 1.0.1
Vendor Notification: 22 February 2011
Vulnerability Type: XSS (Cross Site Scripting)
Status: Fixed by Vendor
Risk level: Medium
Credit: High-Tech Bridge SA - Ethical Hacking & Penetration Testing (http://www.htbridge.ch/)

Vulnerability Details:
The vulnerability exists due to failure in the "/wp-content/plugins/photosmash-galleries/index.php" script to properly sanitize user-supplied input in "action" variable.
User can execute arbitrary JavaScript code within the vulnerable application.
Successful exploitation of this vulnerability could result in a compromise of the application, theft of cookie-based authentication credentials, disclosure or modification of sensitive data.

The following PoC is available:

http://[host]/wp-content/plugins/photosmash-galleries/index.php?action=%3Cscript%3Ealert%28%22XSS%22%29;%3C/script%3E

Solution: Upgrade to the most recent version