The default configuration of Microsoft Windows uses the Web Proxy Autodiscovery Protocol (WPAD) without static WPAD entries, which might allow remote attackers to intercept web traffic by registering a proxy server using WINS or DNS, then responding to WPAD requests, as demonstrated using Internet Explorer. NOTE: it could be argued that if an attacker already has control over WINS/DNS, then web traffic could already be intercepted by modifying WINS or DNS records, so this would not cross privilege boundaries and would not be a vulnerability. It has also been reported that DHCP is an alternate attack vector.
https://exchange.xforce.ibmcloud.com/vulnerabilities/33244
http://www.vupen.com/english/advisories/2007/1115
http://support.microsoft.com/kb/934864
http://news.com.com/Windows+weakness+can+lead+to+network+traffic+hijacks/2100-1002_3-6170229.html
http://isc.sans.org/diary.html?storyid=2517
http://archives.neohapsis.com/archives/isn/2007-q1/0418.html