HTB22847: XSS in IWantOneButton wordpress plugin

[advisory () htbridge ch]

Vulnerability ID: HTB22847
Reference: http://www.htbridge.ch/advisory/xss_in_iwantonebutton_wordpress_plugin.html
Product: IWantOneButton wordpress plugin
Vendor: Daniel Sands ( http://www.danielsands.co.cc/ ) 
Vulnerable Version: 3.0.1
Vendor Notification: 10 February 2011 
Vulnerability Type: XSS (Cross Site Scripting)
Risk level: Medium 
Credit: High-Tech Bridge SA - Ethical Hacking & Penetration Testing (http://www.htbridge.ch/) 

Vulnerability Details:
User can execute arbitrary JavaScript code within the vulnerable application.
The vulnerability exists due to failure in the "/wp-content/plugins/iwant-one-ihave-one/updateAJAX.php" script to 
properly sanitize user-supplied input in "post_id" variable.
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/iwant-one-ihave-one/updateAJAX.php?add=want&post_id=%3Chtml%3E%3Cscript%3Ealert%28document.cookie%29;%3C/script%3E%3C/html%3E