Buffer overflow in src/openttd.cpp in OpenTTD before 0.6.2 allows local users to execute arbitrary code via a large filename supplied to the "-g" parameter in the ttd_main function. NOTE: it is unlikely that this issue would cross privilege boundaries in typical environments.
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.