A buffer overflow in the component hl.exe of Valve Half-Life up to 5433873 allows attackers to execute arbitrary code and escalate privileges by supplying crafted parameters.

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.

Buffer overflow in client for Half-Life 1.1.0.8 and earlier allows malicious remote servers to execute arbitrary code via a long console command.

Buffer overflows in Sierra Half-Life build 1573 and earlier allow remote attackers to execute arbitrary code via (1) a long map command, (2) a long exec command, or (3) long input in a configuration file.

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