Get ready: Microsoft is raising the bar for encryption keys

Great news! Next Tuesday is already Patch Tuesday for September, but Microsoft only has a couple of relatively minor updates lined up. Don’t get too comfortable, though—you need to prepare for the changes Microsoft is making next month for cryptographic keys.

Let’s start with Patch Tuesday. September is a dramatic departure from previous months. Unlike the many months that have been loaded down with multiple Critical updates, or the fact that Internet Explorer has been updated monthly for the past few months, Microsoft only has two security bulletins scheduled for this month.

The last couple of months have each had nine new security bulletins, and the average per month through August is 7.5. Two is a manageable number that will make many IT admins very happy. Throw in the fact that both of the security bulletins are rated as Important, and that they impact software or platforms that many businesses don’t even use, and some IT admins may essentially get this Patch Tuesday off free and clear.

Of course, many IT admins are still trying to catch up from previous months, and can use the break to finish deploying the patches they already have. Then, there’s the Java patch from Oracle that probably needs urgent attention if you haven’t already implemented it.

Paul Henry, a security and forensic analyst with Lumension, has one of those “But wait! That’s not all” sort of logs to throw on the fire as well. “It should also be noted that there are currently nine zero day vulnerabilities in HP’s enterprise products with no patch in sight. Eight of these vulnerabilities have been given the highest risk level rating and they should be keeping IT up at night they’re using any of the affected products.”

But, even if all of your patches and updates are applied, and you’ve done all you can to mitigate the risk of any unpatched vulnerabilities that still exist, your work isn’t done. Qualys CTO Wolfgang Kandek notes in a blog post that Microsoft has new rules going into effect in October which will invalidate many certificates.

Kandek says that a Microsoft Certificate Review project was triggered when Microsoft discovered that the Flame malware was signed by a legitimate Microsoft certificate. Kandek says, “RSA key lengths of under 1024 bits have been broken in the past and are considered to be forgeable.”

To strengthen certificate security and prevent such occurrences in the future, Microsoft will consider any certificate signed with a key less than 1024 bits to be invalid. Andrew Storms, director of security operations for nCircle, explains, “This mean older, legacy systems that rely on weak encryption or keys that are too short will stop working. Fix ‘em now, or be seriously sorry when they stop working in October.”