Wednesday, October 23, 2019

Check your firmware, folks.

So, anyway, a few days ago, I noticed a tweet about a Dell Optiplex 7070 bios upgrade that announced an enhancement of "Added BiosConnect feature which enables connection to without an operating system. This feature also enables downloading a recovery image from the cloud through wired or wireless connection."

I thought that sounded interesting, so I decided to take a look, and sure enough, I quickly found the BiosConnect stuff, but then I found that Computrace had also been added.

Now, Computrace is a good, and helpful program, and if your computer is ever lost, or stolen, you'll be glad you have it, and the ability to download a recovery image to a computer with a broken OS is also useful, but ... one of the truths about computer security is that functionality and security tend to exist in an inverse relationship. In other words, the more functional, or powerful, you make something the less secure it tends to be, and we may be confident that the Bad Guys (tm) will always try to take advantage of such features.

Not only that, but some organizations don't want that sort of functionality in their computers... just in case.

The other interesting thing here is that the previous version of this firmware was 8mb long, and had about 320 exes in it, and the new version is 16mb, and has about 575 exes, so one wonders what other functionality has been added. We're still looking at that.

Again, I'm not saying that Dell or Computrace did anything bad. They just added a lot of functionality.

One of the big problems with firmware security is that most people don't flash their firmware because, (1) they don't know that there's a new version available (unlike monthly OS patches which is a well understood, albeit sometimes problematic, mechanism), and (2) they don't know how to flash their firmware. As an example of that, about every two weeks, we get a fresh upload of the supposedly extinct-since-2016 so-called Lenovo rootkit.

Obviously, you have to patch your firmware, because there will be bugs and vulnerabilities that need fixing, but this shows that you also need to examine what new things are coming in.

We have been conducting audits of "before and after" firmware for some of our customers, and it is proving instructive.

More to follow.

Stay tuned.