Patch Tuesday - February 2014, also, say "buh-bye" to MD5

Last updated at Mon, 24 Jul 2017 14:27:34 GMT

This was a fairly novel Patch Tuesday (calling it interesting might be too strong a word for Patch Tuesday, unless you work in vulnerability management and geek out on these things - in which case, I thought it was interesting).

At first take, it looked like Microsoft would continue the 2014 trend of keeping patch Tuesday relatively light.  There were only 5 advisories this month, two critical, three important.  Emphasis is on the past tense. 

Monday morning, Microsoft updated the advance notification to add two more bulletins.  Basically, they added an IE patch and a OS patch, both marked Critical, Remote Code Execution.  In 8 years of dissecting these announcements I don't recall them ever adding to the advance notification between it's release and the Tuesday of the patches.  There have been several occasions where they have held back on releasing an announced advisory.

I talked this over with some folks in the know, and the message is that something (in the IE patch) came in just under the wire, in terms of testing completeness on Microsoft's side, and due to the criticality of it, they bent their schedule in favour of customer security to get the patch out sooner.  The added OS patch is a variant of one of the IE patches, and shares a CVE.  Reaction to  this could fall into one of two camps, either fear that something is being rushed out the door, or relief that we don't have to wait another month for an IE roll-up, which is a really long time on the internet.

The two critical advisories in the original bulletin were unusual in that they don't touch older versions of Windows or Internet Explorer.  The first (MS14-007) patches a remote code execution vulnerability that affects Windows 7 through to Windows 8.1, including 8.1 RT.  The second (MS14-008), also remote code execution, is actually an issue in Forefront Protection for Exchange Server (2010). 

Given a remote code execution in a perimeter service like Forefront, I'd be inclined to say that this would be the highest priority patching issue this month. However, there is apparently no known exploitation of this in the wild, no known exploit vector, and this was found internally by Microsoft in a code analysis.  So I'm going to call the IE 24 CVE rollup, MS14-010, the highest priority for patching. The second priority is not surprisingly the critical in Windows 7 and later issue (MS14-007), the third is the OS variant of the one CVE in that also affects IE, MS14-011.

The other three issues are all of lower risk and likely lower exploitability, ranging from information disclosure to denial of service and elevation of privilege.  Not to be ignored, but should be of slightly less concern than remote critical vulnerabilities.

On top of all this fun stuff, Microsoft has moved forward with MD5 deprecation and it is now being pushed through Windows update.  MD5 certificates will now be untrusted.  This will affect anything in the chain of trust up to root signing authority if MD5 is used anywhere.  MD5 is a hashing algorithm used to ensure that something (such as an SSL certificate) has not been modified.  Malicious parties would want to modify SSL certificates in order to provide convincing mis-direction so that a user might trust a content provider who is being impersonated.

What this means for users is that, if they are using IE, or another product that relies on Microsoft's cryptography services, and they visit a website which is using SSL where MD5 is used to sign the certificate, they will be warned about visiting an untrusted site.