Microsoft has admitted that a vulnerability in Windows Server 2003 and XP could allow hackers to take control of PCs by luring users to a dangerous website that contains remote execution link.

The software giant announced the vulnerability, which is in the operating systems' Help and Support Centre, in its latest monthly security advisory. The flaw could be triggered from web pages or HTML e-mail, but is apparently a lower threat than the Sasser worm.

Microsoft labelled the vulnerability as important.