Microsoft has said a "critical" flaw in most versions of its Windows operating system could allow hackers to break into personal computers and snoop on sensitive data.
Although no computers were reported to have been compromised, the world's largest software maker warned that Windows NT, Windows 2000, Windows XP and Windows Server 2003 were at risk. Microsoft announced the flaw in its monthly security bulletin published last night.
The company offered software updates to fix the software flaw, which it assigned its most severe rating of "critical."
"It does affect all (current) versions of Windows," said Mr Stephen Toulouse, security program manager for Microsoft's Security Response Center. "We're not aware of anyone affected by this at this time."
Mr Marc Maiffret, co-founder of eEye Digital Security, the company that discovered the flaw, criticised Microsoft for taking more than six months to come up with a patch to fix the problem.
The flaw could allow a hacker to break into a computer running Microsoft's Windows operating system in several ways and then use the compromised machine to run malicious programs and steal or delete key data, Mr Maiffret and other experts said.
Windows users can download the patch for the vulnerability from: http://www.microsoft.com/security