Microsoft began warning Web site administrators on Wednesday that a flaw in its FrontPage extensions could allow an attacker to take control of their servers or cause the computers to seize up! In its 53rd Security Advisory of the year, Microsoft admitted that a serious vulnerability in their SmartHTML interpreter can be exploited to cause a denial-of-service attack on the host Web server if that computer has FrontPage Server Extensions 2000 running. For FrontPage Server Extensions 2002, the same security flaw can also result in the attacker's being able to run the code of their choice, essentially taking over control of the server. &If a request for a certain type of Web file is made in a particular way... it will also cause the SmartHTML interpreter to cycle endlessly, thereby consuming all the server's CPU availability,& according to Microsoft's advisory. The company urged administrators to apply the patch for the problem or run the Internet Information Server lockdown tool, a security application that disables many of the potentially dangerous functions in Microsoft's IIS Web server.