Calling all Microsoft administrators. It's time to spin up your virtual test machines and download, test, and deploy May's batch of Microsoft security updates. This month's theme is IE updates; with a focus on a recent IE zero day vulnerability, as well as a continuation of the "use after free" vulnerability theme I commented on last month.
According to their summary post, Microsoft released ten security bulletins today, fixing around 33 security vulnerabilities in many of their popular products. The affected software includes Internet Explorer (IE), Windows and related components, products from the Office suite (Word, Visio, and Publisher), Lync, and Windows Essentials. Microsoft rates the IE updates as Critical, and the rest as Important.
As I mentioned earlier, today's theme definitely centers around IE. Last week's security video covered how attackers have recently been exploiting a zero day IE8 vulnerability in the wild—most notably against the Department of Labor web site. One of today's updates completely fixes this serious flaw. The other IE update continues to fix more "use after free" vulnerabilities, a class of memory corruption flaws that researchers and attackers have focused on lately. I highly recommend you install today's IE updates immediately, then follow with the Windows and Office updates.
As an aside, Microsoft also released or updated four security advisories today. One of the updates has to do with one of today's bulletins, but the other three are new. Once you're finished handling today's patches, you should check out Microsoft's security advisory page as well.
We'll share more details about today's bulletins in upcoming alerts. Until then, feel free to check out Microsoft's May bulletin summary.