A patch has been released by Microsoft for a flaw in the networking components of its flagship software Windows NT, 2000, XP and Server 2003. The flaw could allow a worm to spread very fast causing chaos similar to that caused by the MSBlaster worm.

Chief Hacking Officer for eEye Digital Security, Marc Maiffret said: "There are more attack vectors and more people that could be affected by this". The company warned Microsoft of the flaw over six weeks ago so a patch could be developed.

This is the second flaw in Microsoft software revealed this month, the first being a flaw in Internet Explorer. This latest flaw is in Microsofts use of the network protocol Abstract Syntax Notation One.