A
vulnerability in the way Windows handles animated cursors puts users at risk
of being pwnd, and several nefarious websites are already trying to exploit the
flaw, according to the SANS Internet Storm Center. The flaw is present on
virtually the entire line of Windows OSes, including Vista, which has been held
up as Redmond's poster child for safe computing.
According to McAfee, Windows users browsing malicious sites using IE
versions 6 or 7 risk having arbitrary code run on their machines. Those using
Firefox are not vulnerable. Microsoft said in an advisory that it is
investigating reports of the flaw. 'Upon viewing a web page, previewing or
reading a specially crafted message, or opening a specially crafted email
attachment the attacker could cause the affected system to execute code,"
Microsoft warns. Files that can exploit the vulnerability are not limited to
those with the .ani extension that come with most programs that animate the
cursor on Windows machines. Some exploits in the wild are reported to be
embedded in jpeg files,
SANS
and Secunia
say in their advisories. Surprisingly, Microsoft said those using IE 7 on Vista
are safe from the vulnerability because of a protected mode, which restricts
where the browser can write files.
This isn't the first time Microsoft's animated cursor format has caused problems. Over two years ago, Microsoft issued patches for a vulnerability with the cursor format that could actually allow remote code execution in Windows NT, Windows 2000, Windows XP, and Windows Server 2003.