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From a security perspective Thunderbolt is one of the worst things that can happen. Imagine being a speaker at a conference where you use your own laptop for a
by gst 15y ago
From a security perspective Thunderbolt is one of the worst things that can happen.
Imagine being a speaker at a conference where you use your own laptop for a presentation and where (at some point in the future) the projector only has a Thunderbolt interface. Are you going to connect your laptop? If you do the projector has basically full access to your laptops memory - and therefore full control over your laptop. Even if you use disk encryption this does not help, as the key is still stored somewhere in memory.
I think that if there's one thing that we've learned in the past two decades it's that physical interfaces should try to provide a little bit of security. With Thunderbolt, all security is traded for a little bit of additional performance.
- eliben 15y agoWhat makes you think the projector "has access to all your memory" any more than any random card has? That's simply not true, and completely depends on the driver. Maybe the projector can get your computer to hang or crash, but it seems to me that building security feature into this isn't very hard, even without sacrificing performance.
- gst 15y agoBecause Thunderbolt is basically an extension of the PCI bus. This means that the protocol _is_designed_ to grant full memory access to external devices (in fact that's the way how the DMA data transfer in Thunderbolt works). With other protocols such as USB or DisplayPort you don't have those issues. Of course, a faulty driver could be used to compromise the system, but the protocol itself is secure.
- Groxx 15y agoDon't USB and Firewire both have DMA as well? This sort of attack has been possible for a long time: http://replay.web.archive.org/20090402130220/http://storm.net.nz/projects/16 http://replay.web.archive.org/20090402130220/http://storm.ne...
- wtallis 15y agoDMA has historically been Firewire's one big advantage over USB, which even in the 3.0 revision doesn't do DMA.
- gst 15y agoYes, Firewire also uses DMA, but hardly anyone uses Firewire anymore :) And even the people who still use Firewire typically don't use it to connect to third-party devices (such as projectors). With USB I must to admit that I'm not 100% sure. I've always assumed that USB does not use DMA, but after googling it it seems that there's some DMA support in USB. Would be interesting to know if there's some kind of fallback mode - e.g., in order to use a less efficient (but more secure) protocol if the computer does not support (or enable) DMA.
- zdw 15y agoTurning on the firmware password on a Mac blocks Firewire DMA access to main memory, if you're concerned about that.
- wtallis 15y agoIOMMU support is going to be universal long before DisplayPort support (let alone Thunderbolt support) is even common for projectors.
- haberman 15y agoThe article mentions this issue explicitly. According to http://en.wikipedia.org/wiki/Thunderbolt_(interface)#Security http://en.wikipedia.org/wiki/Thunderbolt_(interface)#Securit..., Nehalem (and later) CPUs have an IOMMU that let the OS choose which parts of memory to map into the device's address space. In other words, this issue has been dealt with: you don't expose all of your laptop's memory to Thunderbolt devices.