Stack-based buffer overflow in the ValidateMove function in frontend/move.cc in GNU Chess (aka gnuchess) before 6.2.4 might allow context-dependent attackers to execute arbitrary code via a large input, as demonstrated when in UCI mode.
Buffer overflow in GNU Chess (gnuchess) 5.02 and earlier, if modified or used in a networked capacity contrary to its own design as a single-user application, may allow local or remote attackers to execute arbitrary code via a long command.