source: http://www.securityfocus.com/bid/26140/info

rNote is prone to multiple cross-site scripting vulnerabilities because the application fails to sufficiently sanitize user-supplied input.

Exploiting these vulnerabilities may allow an attacker to perform cross-site scripting attacks on unsuspecting users in the context of the affected website. As a result, the attacker may be able to steal cookie-based authentication credentials and to launch other attacks.

rNote 0.9.7.5 is vulnerable; other versions may also be affected. 

http://www.example.com/rnote/rnote.php?d=<script>alert("RxH")</script 
http://www.example.com/rnote/rnote.php?u=<script>alert("RxH")</script