server/sv_main.c in Quake3 Arena, as used in ioquake3 before r1762, OpenArena, Tremulous, and other products, allows remote attackers to cause a denial of service (network traffic amplification) via a spoofed (1) getstatus or (2) rcon request.
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.