Will one fix the latest windows zero day?
Remember the good ol’ days (last month), when Microsoft would only release a few bulletins on Patch Day. This month won’t be like that.
According to this month’s advanced notification, Microsoft intends to release a dozen security bulletins next Tuesday, February 8th. Ten of the bulletins will fix security flaws in Windows (or components that ship with it), one bulletin covers vulnerabilities in Internet Explorer (IE), and the remaining one fixes flaws in Office. Microsoft rates three of the bulletins as Critical, and the others as Important.
On a related note, late January Microsoft released a Security Advisory (their form of an early security warning for unpatched issues) describing a zero day web-related vulnerability in Windows. The flaw involves the Windows MHTML or MIME HTML component, which is used to handle special web pages that include both HTML and MIME (typically pictures, audio, or video) content contained in one file. If an attacker can entice you to visit a specially crafted web-page, or click a malicious link, he could exploit this flaw in much the same way he might exploit a Cross-Site Scripting (XSS) vulnerability ; t0 steal your cookies, redirect your browser to malicious sites, or essentially take any action you could on a web site.
As mentioned, Microsoft hasn’t released a patch for this flaw yet, but I am hoping that they do during next Tuesday’s Patch Day. Until they do, be sure to check out the “Suggested Actions” section of their advisory, which points to a FixIt solution that should mitigate the risk of this unpatched flaw.
Whether or not Microsoft includes the MHTML patch in next week’s Patch Day, I highly recommend you prepare your staff for a full day of testing and patching. With twelve bulletins to navigate, it will probably take awhile to get your Windows network up to date.
We’ll know more about these bulletins next Tuesday, and will publish alerts about them here. — Corey Nachreiner, CISSP