Buffer overflow in the UGameEngine::UpdateConnectingMessage function in the Unreal engine 1, 2, and 2.5, as used in multiple games including Unreal Tournament 2004, Unreal tournament 2003, Postal 2, Raven Shield, and SWAT4, when downloads are enabled, allows remote attackers to execute arbitrary code via a long LEVEL field in a WELCOME response to a download request.

The UCC dedicated server for the Unreal engine, possibly 2003 and 2004, on Windows allows remote attackers to cause a denial of service (continuous beep and server slowdown) via a string containing many 0x07 characters in (1) a request to the images/ directory, (2) the Content-Type field, (3) a HEAD request, and possibly other unspecified vectors.

Stack-based buffer overflow in the logging function in the Unreal engine, possibly 2003 and 2004, as used in the internal web server, allows remote attackers to cause a denial of service (application crash) via a request for a long .gif filename in the images/ directory, related to conversion from Unicode to ASCII.

Directory traversal vulnerability in manifest.ini in Unreal engine allows remote attackers to overwrite arbitrary files via .. (dot dot) sequences in a UMOD (Unreal MOD) file.

The Unreal Engine, as used in DeusEx 1.112fm and earlier, Devastation 390 and earlier, Mobile Forces 20000 and earlier, Nerf Arena Blast 1.2 and earlier, Postal 2 1337 and earlier, Rune 107 and earlier, Tactical Ops 3.4.0 and earlier, Unreal 1 226f and earlier, Unreal II XMP 7710 and earlier, Unreal Tournament 451b and earlier, Unreal Tournament 2003 2225 and earlier, Unreal Tournament 2004 before 3236, Wheel of Time 333b and earlier, and X-com Enforcer, allows remote attackers to execute arbitrary code via a UDP packet containing a secure query with a long value, which overwrites memory.

Epic Games Unreal Engine 226f through 436 allows remote attackers to cause a denial of service (CPU consumption or crash) and possibly execute arbitrary code via (1) a packet with a negative size value, which is treated as a large positive number during memory allocation, or (2) a negative size value in a package file.