In computer security an programming, a buffer overflow, or buffer overrun, is an anomalous condition where a process attempts to store data beyond the boundaries of a fixed-length buffer. The result is that the extra data overwrites adjacent memory locations. The overwritten data may include other buffers, variables and program flow data, and may result in erratic program behavior, a memory access exception, program termination (a crash), incorrect results or ― especially if deliberately caused by a malicious user ― a possible breach of system security.