A week ago, the advance notification for Microsoft's February Patch Tuesday promised no Microsoft Internet Explorer patches. At the time, I wrote that it was surprising, especially given that there were no IE patches in January either. I was optimistic that this was the beginning of a new trend, a new era for IE security.
I was wrong.
On Feb. 11, Microsoft did in fact include IE in its February Patch Tuesday, with an update for no less than 24 vulnerabilities. As it turns out, even with the 24 fixed vulnerabilities, Microsoft still missed at least one. There is now an actively exploited zero-day attack against a vulnerability in IE.
"Microsoft is aware of targeted attacks against Internet Explorer, currently targeting customers using Internet Explorer 10," Microsoft wrote in an email to eWEEK. "We are investigating and we will take action to help protect customers."
Security vendor FireEye first publicly reported the zero-day on Feb. 13. The zero-day is being used in what is known as a "watering-hole" attack, where visitors to a legitimate site are being compromised.
"We believe the attack is a strategic Web compromise targeting American military personnel amid a paralyzing snowstorm at the U.S. Capitol in the days leading up to the Presidents Day holiday weekend," FireEye researchers wrote in a blog post.
According to FireEye's analysis, the attack leverages a Use-After-Free memory corruption flaw in IE 10. Use-After-Free flaws enable an attacker to abuse memory space from properly allocated program space. As part of the February Patch Tuesday update, Microsoft had already patched 21 flaws that it collectively grouped together as "Multiple Memory Corruption Vulnerabilities in Internet Explorer."
FireEye isn't the only security vendor that claims to have knowledge of the CVE-2014-0322 zero-day issue. In a blog post of its own, security vendor Websense claims to have been aware of the same issue since at least Jan. 20.
According to the Websense analysis, the attack is targeting organizations associated with the French aerospace association GIFAS.
Currently as a zero-day flaw, there is no patch in IE 10 to directly fix the CVE-2014-0322 issue. That said, users are not totally helpless. The flaw only targets IE 10, so if a user is able to upgrade to IE 11, the risk can be eliminated.
Additionally, if a user is running IE with Microsoft's Experience Mitigation Toolkit (EMET), the attack cannot be executed. EMET provides an additional wrapper of sandbox security for IE and is exceptionally difficult for attackers to bypass. In fact, Hewlett-Packard is so eager to find research demonstrating that EMET can be bypassed that it is offering a $150,000 reward at the upcoming Pwn2own hacking competition to anyone who can defeat it.
Overall, this new zero-day issue proves one thing: IE, despite a lull in security patches in January, is still very much a target.
Sean Michael Kerner is a senior editor at eWEEK and InternetNews.com. Follow him on Twitter @TechJournalist.