Microsoft has issued four critical security updates that patch at least eight vulnerabilities in the various Windows operating systems and Office programs. If you use either, you'll want to install them sooner rather than later.

The most serious of the updates is one patching Microsoft's graphics device interface, the component in Windows that renders JPEGs and many other types of images. The GDI engine contains five separate vulnerabilities that could allow an attacker to install malware on a system when it loads a specially crafted image file.

For whatever reason, GDI flaws seem to be the vulnerability of choice of attackers. Earlier this year, after Microsoft repaired a previous image-rendering bug, exploits found their way onto the net two days later. Four years ago, a toolkit exploiting a similar GDI flaw was released shortly after it was patched. Take note: There seems to be a pattern here of reverse engineering these types of updates to create in-the-wild attack code.

Microsoft also patched a bug in multiple versions of Office that could lead to remote code execution when a user clicks on a maliciously crafted OneNote protocol handler. The remaining two bulletins fix flaws in Windows Media Player and Windows Media Encoder, both of which could also allow an attacker to remotely install malware on a victim's machine.

As always, the SANS Internet Storm Center has a highly readable summary, which is available here.

This month's Patch Tuesday batch was notable in that all four updates carried the "critical" rating, Microsoft's most serious severity designation. Lest Apple users feel left out, that company has issued a raft of its own security fixes, and some of those look equally important. Looks like household-appointed admins will be working overtime today. ®

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