10th Gen Honda Civic Updates Are Signed with AOSP Test Keys

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llibrick about 5 hours ago 25 commentsRead Article on juniperspring.org

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Discussion (25 Comments)Read Original on HackerNews

librick•about 5 hours ago

To update 10th-gen Honda Civics, Honda ships updates on specially-formatted USB drives. They're essentially Android 4.2.2rc1-era recovery packages with some Honda-added version checks (which can be spoofed). The packages are signed with the publicly-known AOSP test key, so with physical access to the front USB port you can sign and flash your own package for arbitrary code execution on the headunit. This doesn't require root/su. I've run it end-to-end on my own 2021 Civic and separately confirmed an official EU update file carries the AOSP test-key signature. Tooling and writeup in the post.

DANmode•about 1 hour ago

> AOSP

Android Open Source Project

for those outside the bubble!

vel0city•about 2 hours ago

A number of other cars' infotainment systems are also based on ASOP. I remember downloading updates for my Hyundai which were also essentially Android images

hparadiz•about 2 hours ago

The head units themselves are very dated and simply could not run recent versions of Android. I have a 2020 and I'm always eyeing up the after market units which are all better in every way.

userbinator•about 2 hours ago

IMHO this is a good sign(!?) that they didn't even think about locking down their systems against the owner.

varenc•23 minutes ago

It's not good that they allow anyone that happens to be in your car briefly root access. It'd be live having an always-on laptop in your office with a open shell on it.

They should have provided some mechanism for the real owner to approve updates if the updates aren't all trusted by default.

BobbyTables2•about 2 hours ago

I’ve heard product managers proudly proclaim their firmware was signed using the corporate internal signing service (good).

Of course, the question explicitly being asked (related to internal mandate) was if the firmware was signed — not if the firmware update process actually checked the signature (it certainly did not).

Koffiepoeder•13 minutes ago

I once came across a similar "solution". The signing algorithm was directly executed from the update package. How would we otherwise be able to update the signature algorithm? Worst part was that it was correct at some point. It was an introduced regression because of a signature change due to " post-quantum safe" signatures now being required by the security team.

mschulkind•about 2 hours ago

I'm surprised someone named BobbyTables2 wouldn't go straight for the proper way to check email PGP signatures...

naturalmovement•about 1 hour ago

If I'm reading the room, the sentiment is Honda is incompetent and their cars are security holes on wheels. But if the opposite happened, they would be technofascists locking us out of our own cars, a 30 post sub-thread "this is why I drive a 1999 Ford Ranger" would ensue, and someone would be investigating it as a possible GPL violation. Do I have this right?

It's also a good assumption most people airing such complaints have never eaten in a restaurant fancy enough to have valet parking, let alone evil valets.

That said, are evil valets known to tote around USB drives, or would they more likely use your navigation system to drive back to your empty house and clean it out while you're eating?

TheDong•11 minutes ago

I think the evil valet risk isn't real, but this could be part of a chain-of-attack in some scenarios, mainly rental cars.

Like, sure, if you're just going to use it to spy on the user, you could also rent a rental car and leave a recording device under the floormat, or hidden behind the head unit, or whatever.

But if you have an Apple Carplay exploit, where someone tethering their phone to the car can be compromised, renting a car and flashing a malicious OS to exploit the phones of people who come after you could maybe be a real attack. It's kinda hard to get people to otherwise connect to a malicious infotainment system with carplay, so if you have an exploit that requires that, this could be part of it...

Except actually, no, if you have a carplay exploit, just rent the car, and rewire the USB port to go through a flipper zero or whatever and don't bother reflashing the car's software, that's just as easy.

... So yeah, I guess I agree with you, even in the rental car scenario, where this seems like it would be worst, your attacker might as well just hide something in the car instead of flashing the software.

Nition•1 minute ago

Yeah ultimately society really relies on the fact that most people aren't actively trying to be evil.

hnav•about 2 hours ago

Wonder how good the rest of the security is. The head unit is likely hooked up to a CAN gateway, can it call into telematics. Maybe find some novel way to abuse carplay/aa to call home.

TheDong•9 minutes ago

If you have physical access to a car and want to phone home, may I recommend leaving a gps tracking device under the floormat.

It works on more brands of cars too than just one gen of honda civics, and probably quicker to install.

hankbond•about 3 hours ago

Seeing more and more projects eschew code docs with the idea that "well architected code can be queried by LLMs" and stick to more functional runbook style docs. It really is unlikely that at any given point all of the docs of a project are up to date with the code.

I'm generally aligned with this, but it is predicated on the whole "well architected" code part.

jmalicki•about 2 hours ago

I'd rather see unit tests as documentation.

The test can show intended use, show interesting corner cases, and I know it is up to date because it is constantly running and passing.

I think that is a huge underrated benefit of adding a lot more testing.

If I think a developer is going to ask a question of how something works, or about a corner case, isn't that deserving of a test, so they can just see proof of the answer to their question immediately rather than trying to re-derive it?

nucleardog•21 minutes ago

I think unit tests are documentation in the same way that a Dockerfile is... it's not. The tests don't paint the bigger picture, explain why, etc.

That said, if you pitched me something like a Jupyter notebook style doc where tests validating the claims of the documentation were inline, I'd totally buy into that.

hankbond•about 2 hours ago

You know what, you are right on the money with that. I think if you expand to include functional/smoke/e2e tests, that covers pretty much everything documentation is supposed to be.

Just by running them you can measure if they are in or out of sync with the code (well, if they were written correctly).

EPWN3D•about 2 hours ago

LLMs are great at writing unit tests.

t1234s•about 3 hours ago

Could you use this to get a version of lineage OS running on it?

runjake•about 1 hour ago

You could, but if this unit is anything like it is in my CR-V, and its most likely the same, it's an ancient slow OMAP processor and 4GB of RAM (IIRC).

Edit: Looks like a Tegra 3 in this one, but my bet is meager RAM.

baby_souffle•about 3 hours ago

Yes, but it'll still be using their kernel so not all functionality from lineage might work.

DANmode•about 3 hours ago

EvilValet, sick

rootsudo•about 3 hours ago

Yeah jealous he even got to name an attack surface. Damn.

bri3d•about 2 hours ago

Hyundai head units at one point used an RSA key you got by googling “RSA key” (no joke: https://programmingwithstyle.com/posts/howihackedmycar/ ), an honestly even more amazing mistake since it required effort rather than just a default.