source: http://www.securityfocus.com/bid/13154/info

A remote denial of service vulnerability is reported to affect the LG U8120 Mobile Phone. The report indicates that the issue manifests when an affected phone processes a malicious MIDI file. 

The following instructions are available:
To perform the attack from LG U8120:
(WARNING: DOING THIS OPERATIONS YOU CAN BLOCK YOUR DEVICE!
TO RESET IT USE THIS CODE: 277634#*#)

1- Save a mms draft with a dummy midi file
2- Connect mobile phone to PC and overwrite the dummy file with 'lgfreeze.mid'.
3- Send the mms draft.