OpenTTD before 1.0.1 does not properly validate index values of certain items, which allows remote authenticated users to cause a denial of service (daemon crash) or possibly execute arbitrary code via a crafted in-game command.
Unspecified vulnerability in the NormaliseTrainConsist function in src/train_cmd.cpp in OpenTTD before 0.7.5-RC1 allows remote attackers to cause a denial of service (daemon crash) via certain game actions involving a wagon and a dual-headed engine.