Security Experts:

Microsoft Plans Critical IE Patch Tuesday Update

Microsoft is planning to release nine security bulletins this month as part of its Patch Tuesday release.

Just two of the bulletins are rated 'critical' - one affecting Internet Explorer and the other Microsoft Windows - and both of those address remote code execution issues. The seven other bulletins are rated as 'important' and cover vulnerabilities in Microsoft Office, Windows, Microsoft Security Software and Microsoft Server Software.

"Once again there is an IE patch which is rated critical, but this one differs from last month’s incarnation by applying to all supported versions of IE (6-10) on the relevant platforms, including IE 10 on Windows 7 and 8," said Ross Barrett, Rapid7’s senior manager security engineering. "Due to the widespread use of IE and subsequently high degree of exposure for any group or individual using it, combined with the severity, this is where I would prioritize patching efforts."

"Since there are only two critical advisories this month, it follows that the other critical issue which affects all versions of Windows from XP/2003 to 7/2008R2 is the next highest patching priority," he added. "It’s most likely that this is another parsing library bug (hence the required restart), though there is an outside chance that this could prove to be a truly worm-able issue affecting a service available on all Windows versions."

Though only two of the patches have been classified as critical, the sheer number of patches planned for this month is noteworthy, said Alex Horan, senior product manager at CORE Security.

"Large numbers of updates lead to more administration and ultimately delays," he said. "This can allow critical vulnerabilities to be exploited while less significant concerns simply cloud the security picture."

Besides bulletin one, he also advised organizations to pay attention to bulletin 8, which he argued may represent one of the first reported vulnerabilities for Microsoft Office Web Apps 2010, which "would be significant in and of itself." 

The security updates are slated to be released Tuesday, April 9.