An Australian bug expert has discovered a security flaw in Microsoft's latest consumer operating system, Windows ME, which makes it vulnerable to 'denial-of-service' style attacks.The discovery was made by Andrew Griffiths, who posted his findings on Bugtraq - a website designed to track system vulnerabilities. Griffiths claims the problem occurs when Windows ME runs Microsoft's WebTV application. The flaw allows malicious users to flood the PC's processor and bring it to a halt, by sending a type of data formatted with Uniform Datagram Protocol (UDP). The attack is technically similar to a 'denial-of-service' attack in that it makes the receiver's port invalid by sending the UDP packet data to it. According to US newswires, security experts have confirmed computers protected by firewalls are unlikely to be vulnerable.