Off-by-one error in the GeoIP module in the AMX Mod X 1.76d plugin for Half-Life Server might allow attackers to execute arbitrary code or cause a denial of service via unspecified input related to geolocation, which triggers an error message from the (1) geoip_code2 or (2) geoip_code3 function, leading to a buffer overflow.

Cross-site scripting (XSS) vulnerability in auth.w in djeyl.net WebMod 0.48 Half-Life Dedicated Server plugin allows remote attackers to inject arbitrary web script or HTML via the redir parameter.

The SV_CheckForDuplicateNames function in Valve Software Half-Life CSTRIKE Dedicated Server 1.6 and earlier allows remote authenticated users to cause a denial of service (infinite loop and daemon hang) via a backslash character at the end of a connection string to UDP port 27015.

The Half-Life engine before July 7 2004 allows remote attackers to cause a denial of service (server or client crash) via an empty fragmented packet.

The SV_CheckForDuplicateNames function in Valve Software Half-Life CSTRIKE Dedicated Server 1.1.1.0 and earlier allows remote authenticated users to cause a denial of service (infinite loop and daemon hang) via a certain connection string to UDP port 27015 that represents "absence of player informations," a related issue to CVE-2006-0734.

Half-Life Server 1.1.1.0 and earlier allows remote attackers to cause a denial of service (resource exhaustion) via multiple responses to the initial challenge with different cd_key values, which reaches the player limit and prevents other players from connecting until the original responses have timed out.

Format string vulnerability in Sierra Half-Life build 1573 and earlier allows a remote attacker to execute arbitrary code via the map command.

Buffer overflow in Half Life dedicated server before build 3104 allows remote attackers to execute arbitrary commands via a long rcon command.

Format string vulnerability in Half Life dedicated server build 3104 and earlier allows remote attackers to execute arbitrary commands by injecting format strings into the changelevel command, via the system console or rcon.