source: http://www.securityfocus.com/bid/54776/info

Mahara is prone to multiple cross-site scripting vulnerabilities and an HTML-injection vulnerability because it fails to properly sanitize user-supplied text.

Successful exploits will allow attacker-supplied HTML and script code to run in the context of the affected browser, potentially allowing the attacker to steal cookie-based authentication credentials or control how the site is rendered to the user. Other attacks are also possible.

Mahara versions prior to 1.5.2 and prior to 1.4.3 are vulnerable. 

 http://www.example.com/mahara-1.5.1/mahara-1.5.1/htdocs/admin/users/changeuser.php?xss=\x22\x3E\x3C\x68\x31\x3E\x58\x53\x53\x3C\x2F\x68\x31\x3E\x3C\x69\x6D\x67\x20\x73\x72\x63\x3D\x39\x20\x6F\x6E\x65\x72\x72\x6F\x72\x3D\x61\x6C\x65\x72\x74\x28\x22\x58\x53\x53\x22\x29\x3E