Researcher upset by Windows DNS patchMarch 17, 2009 – 7:35 AM
One of the patches Microsoft issued last week is nothing of the sort, according to a researcher who has accused Microsoft of making functionality a higher priority than security.
According to Tyler Reguly, a senior security engineer with nCircle Security, last Tuesday’s MS09-008 update does not fix the problem for all users, many of whom may not realise that they’re still vulnerable to attack.
“When you get a patch from a vendor, you expect it to provide some level of security,” said Reguly. “But MS09-008 only mitigates the problem, it doesn’t patch it.”
MS09-008, one of three security updates released March 10, addressed four separate flaws in Windows’ DNS and WNS servers, and required that network administrators patch all currently-supported server editions of Windows, including Windows 2000 Server, Server 2003 and Server 2008.
Reguly has taken exception with the part of the update that addresses a vulnerability in the WPAD (Web Proxy Auto-Discovery) functionality of Windows DNS Server.
“WPAD is a way to automatically configure proxy servers on machines,” he explained. “When the browser, like Internet Explorer, is configured to ‘Automatically Detect Settings,’ it will look for wpad.company.com and attempt to resolve and pull down a configuration file. But if an attacker can manipulate the WPAD entry, all the traffic from those machines will go through his server. That would let him run ‘man-in-the-middle’ attacks to steal passwords or any other information.”