server/svmain.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 FSCheckFilenameIsNotExecutable function in qcommon/files.c in the ioQuake3 engine 1.36 and earlier, as used in World of Padman, Smokin' Guns, OpenArena, Tremulous, and ioUrbanTerror, does not properly determine dangerous file extensions, which allows remote attackers to execute arbitrary code via a crafted third-party addon that creates a Trojan horse DLL file.

sys/sysunix.c in the ioQuake3 engine on Unix and Linux, as used in World of Padman 1.5.x before 1.5.1.1 and OpenArena 0.8.x-15 and 0.8.x-16, allows remote game servers to execute arbitrary commands via shell metacharacters in a long fsgame variable.

Two security vulnerabilities in the ioquake3 engine may affect your quake3 and/or openarena packages. I will comment with more details when I have confirmed that this bug is not public.