MultiTheftAuto 0.5 patch 1 and earlier allows remote attackers to cause a denial of service (application crash) via a crafted command 40 that causes a -1 length to be used and triggers an out-of-bounds read.

MultiTheftAuto 0.5 patch 1 and earlier does not properly verify client privileges when running command 40, which allows remote attackers to change or delete the message of the day (motd.txt).