Windows DNS Server in Microsoft Windows 2000 SP4, Server 2003 SP1 and SP2, and Server 2008, when dynamic updates are enabled, does not restrict registration of the "wpad" hostname, which allows remote authenticated users to hijack the Web Proxy Auto-Discovery (WPAD) feature, and conduct man-in-the-middle attacks by spoofing a proxy server, via a Dynamic Update request for this hostname. |