https://www.exploit-db.com/exploits/21572
http://www.cnnvd.org.cn/web/xxk/ldxqById.tag?CNNVD=CNNVD-200210-169

Half-LifeServer1.1.1.0及其之前版本存在漏洞。远程攻击者借助多个到具有不同cd_key值的原始挑战的响应导致服务拒绝（资源耗尽），该漏洞可达到播放限度且直到原始响应超时才允许其他播放器连接。

source: http://www.securityfocus.com/bid/5076/info

Half-Life is a popular game distributed and maintained by Valve Software. It includes features that allow users to game locally, or in distributed network environments. Valve Software also distributes a dedicated server product.

A denial of service vulnerability has been reported in some versions of the Half-Life server. A remote party may create a large number of new users on a specific server through spoofing the connection conversation. As servers contain a set limit on the maximum number of players, server resources will be exhausted, and legitimate players will not be allowed to join the game. 

https://github.com/offensive-security/exploit-database-bin-sploits/raw/master/bin-sploits/21572.zip

来源:BID
名称:5076
链接:http://www.securityfocus.com/bid/5076
来源:XF
名称:halflife-mulitple-player-dos(9412)
链接:http://www.iss.net/security_center/static/9412.php
来源:BUGTRAQ
名称:20020620Half-lifefakeplayersbug
链接:http://archives.neohapsis.com/archives/bugtraq/2002-06/0248.html