back to article Need a green traffic light all the way home? Easy with insecure street signals, say researchers

Criminals monkeying with traffic lights are a staple of cinema: the 1969 Italian Job and Luc Besson's Taxi are particularly fine examples. Now researchers have demonstrated that fact is much less glamorous – and simpler – than fiction. Youtube clip from the Italian Job In a paper [PDF] delivered to the USENIX Security 2014 …

Why the different standards?

While this might be technically feasible, it is as illegal as stealing stop signs - something that got people long stretches in prison.

http://www.nytimes.com/1997/06/21/us/3-are-sentenced-to-15-years-in-fatal-stop-sign-prank.html

What we're seeing here is the expectation that electronics be held to a higher standard than what it is replacing.

Nobody hassled the stop sign makers for having bolts that could be unscrewed. Why did they not use "security" bolts? Why did they not weld the signs instead of using bolts? Were they negligent in making signs that could be disassembled?

This is one of the really hard parts of embedded design. People are relatively forgiving when cables snap , but get all lawyered up when electronics and software fail.

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Re: Why the different standards?

To unbolt a stop sign I have to visit your town and be visible on the street by the stop sign with a spanner for a significant time.

To do this attack on all and any city in america I just need to be one of a billion anonymous people sitting at a computer in a country on the other side of the Pacific.

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Re: Why the different standards?

>This is one of the really hard parts of embedded design. People are relatively forgiving when cables snap , but get all lawyered up when electronics and software fail.

That's the key word though, innit? Hard. Not impossible. It's not impossible to predict every possible physical scenario that might cause a given cable to snap, but it's damn hard I reckon. Software, on the other hand, only ever does exactly what you program it to do; "I didn't know it might behave that way" is not so forgivable because the knowledge definitely exists, you just didn't know it. When a system fails due to badly-written software, it's comparable to a cable snapping because the engineer didn't grok that metals are only ductile up to a point.

IMHO the real double standard is that programmers aren't held to such high practical standards as civil engineers during the design and build phase. We can write shit code all day long and only ever be called on it when/if something goes horribly wrong.

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Re: Why the different standards?

"IMHO the real double standard is that programmers aren't held to such high practical standards as civil engineers during the design and build phase. We can write shit code all day long and only ever be called on it when/if something goes horribly wrong."

Really??

Roads get pot holes in them. That is a civil engineering failure. Traffic lights fail for electrical reasons, as do power grids. Every mechanic in town currently has a car or two being repaired because mechanical stuff failed.

It always comes down to a compomise between costs and features. We could make roads for $5bn per km that would never get pot holes o break during eathquakes but we don't. We could make $5000 water pumps for cars that would never wear out, but we don't.

Same deal with software: in this age of 99c apps, nobody wants to pay $5M to develop a nuke-proof traffic light system.

The only real difference is that Joe Sixpack can understand that roads will fail and that mechanical stuff wears out, but the failure modes of software are far less obvious. What they don't understand, they don't make allowances for.

Really good software engineers are as skilled as top-end surgeons and certainly more skilled than bottom-of-the-barrel lawyers. The skilled surgeon will get paid $800/hr or more the crap lawyer will get paid $300/hr. Yet a really top sw eng will not be getting a quarter of that. Why? Same reason.

Software is invisble. You can't see software duct tape. People do not appreciate the difference between working and working well. As a result people will not pay for it.

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Re: Why the different standards?

In your example you're stealing a bit of physical property, without which there's an increased risk of accidents. What the article is talking about, if you were doing the clear green light route at least, wouldn't have any theft and wouldn't increase the risk because it works with the traffic light's systems. You wouldn't have green from every direction, it would be green for you and red for others

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Re: Why the different standards?

What we're seeing here is the expectation that electronics be held to a higher standard than what it is replacing.

Actually we've yet to see that anywhere. Think of all the recall actions of cars due to defective tyres, etc. and then point out something comparable in the software industry.

The US has the concept of unlimited liability which is now coffee containers warn you that hot liquids are dangerous and kitchen knives come with safety warnings. So far the software industry has been able to weasel its way out of similar cases by releasing updates that fix whatever problems. But, unless the law is changed to prevent unlimited liability, that state of grace is bound to end sometime.

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Re: Why the different standards?

Wrong. This does not affect any and all cities in America. This could possibly work in several small cities that have opted for stop lights to be controlled via signal and are too lazy or stupid to change default settings. There are other "hacks" that work better, namely the strobe which affects more stop lights than this would in my opinion.

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Re: Why the different standards?

Also, they can use fasteners which need a specific "secure" tool to unfasten. Like all those secure fasteners used to hold together electical gadgets.

Just go read the story again and watch how many times "default passwords" are mentioned, and left un-changed when the system is installed, and so can be used by a hacker. It's possible that manufacturers have assumed the system operators would not be stupid: this is more a stupidity problem than a standards problem.

Not that the standards in the industry are all that wonderful...

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Re: Why the different standards?

"We can write shit code all day long and only ever be called on it when/if something goes horribly wrong."

Most of the time, shit programmers aren't called on it even then.

Traffic light control is a safety-of-life issue. This kind of thing can expose local authorities to unlmited liabilities (although it's important to note that most traffic light systems will fire a crowbar circuit if simultaneous greens are attempted - it's better to blow the fuses than allow it to happen)

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Re: Why the different standards?

" unless the law is changed to prevent unlimited liability, that state of grace is bound to end sometime."

Now the vulnerability has been publically disclosed, the clock is ticking.

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Re: Why the different standards?

But it is not quite that simple.

Trafic intersections controlled by lights operate in 'phases' where one or more light heads can be green. Eg a crossroads where there is not just one approach green at a time - usually the opposite approach is paired up. In many junctions there are all sorts of combinations of flow. Then there are pedestrian phases.

IF the hacker can find the level in the control system that makes their own aproach green and all others red, then that may be OK, but it would require more study of every junction;s setup.

PS, will people pleas stop flashing their lights (or horn) at roadwork temporary lights - in Europe, its will not work, and never has. (See my username - I design them).

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Pint

Re: Why the different standards?

YAAC missed the wireless bit: "...sitting at a computer in a country on the other side of the Pacific."

Wow, that's quite the 5.8 GHz antenna you have there. Or did you use the 900 MHz link? How many gigawatts did you need? Did you use Moon Bounce? How did you maintain pulse coherence when bouncing high speed data off the Moon? Did you pre-distort it? Amazing; there may be a Nobel prize in that single accomplishment. Wow.

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Stop

Re: Why the different standards?

" Trafic intersections controlled by lights operate in 'phases' where one or more light heads can be green. Eg a crossroads where there is not just one approach green at a time - usually the opposite approach is paired up."

Not anymore in Swansea (UK). Most of the lights are being changed to a 4 phase rather than 2 phase (ignoring the pedestrian phases)

Is this happening elsewhere in the UK? It's bloody ridiculous, and I'm wandering if it's dumbing down because someone managed to sue the council when they turned right into oncoming traffic, hit someone, but argued 'the light was green'. it wouldn't surprise me...

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Re: Why the different standards?

A crossroads near me is 2 phase and would work much better as 4 phase. You have someone who wants to turn right, but can't because there is traffic on the other side of the road. That means the cars behind it who want to turn left or go straight on can't move either, because they are stuck behind the car that can't turn right. There isn't enough space for filter lanes.

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Re: Why the different standards?

"A crossroads near me is 2 phase and would work much better as 4 phase. You have someone who wants to turn right, but can't because there is traffic on the other side of the road."

Ah, fair point. I should have mentioned that the junctions I'm talking about are large ones, with both filter left and right lanes on at least the main junctions. Even then, I agree that filter lanes are useful when the traffic is heavy, but to arrive at one of the many 4 phase lights that have just turned red, at night when you are the only one on the road is annoying to say the least, and these junctions never used to be this way!

Still, this is the council that decided to reverse the traffic flow on the main dual-carriageway, and then claim it has nothing to do with the pedestria fatalities that have occurred there....

http://www.southwales-eveningpost.co.uk/Pressure-traffic-change-grows/story-21027640-detail/story.html

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Re: Why the different standards?

Really? I thought the article stated they had to be using compatible hardware as well as being in-range of the wireless communications in the first place. What you're saying is actually false. These systems aren't communicating with each other 'over the internet', as what you're saying would imply, and you're entire point is actually incorrect. You still need to travel to the applicable city/state and be within range.

What you're saying is like saying you can hack any and all (broadcasting) wireless routers from anywhere in the world regardless of rather or not the router is connected to the internet. Nonsense.

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Re: Why the different standards?

"Nobody hassled the stop sign makers for having bolts that could be unscrewed."

Why should they? It's the stop sign INSTALLERS who failed in this case.

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Given that this could cause crashes

All members of Society should demand that something is done about it - if only for our Self Preservation.

(The one with the keys to the classic mini in the pocket)

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Re: Given that this could cause crashes

There's no reason for this to cause crashes. Test it out at 3am and make sure the other signals turn to red.

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Re: Given that this could cause crashes

Ignoring the fact that my title was mostly setup for a joke...

...yes you could hack the lights in a way that didn't cause problems. But that assumes that the person doing the hacking is being responsible. Except the really responsible thing would be to leave them alone. Get enough people messing around with them and someone will eventually decide that doing something silly in rush hour would be fun.

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Re: Given that this could cause crashes

"The one with the keys to the classic mini in the pocket"

Errr ... you don't need keys to get in or start an original Mk1 Mini. And it don't understand anything less than 12 real live volts up its distributor ;-)

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a team led by University of Michigan computer scientist Alex Halderman has found that traffic signals and their controllers can be hijacked in minutes.

This needs to be qualified by a statement that they've taken over a particular system used in a particular location. As it's written it implies that what they've done can be used on any traffic signal site, anywhere in the world. There are many different traffic signal control systems used the world over. While they are all potentially just as insecure, the outcomes of this exercise are relevant only to the system that was tested.

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(Written by Reg staff) Silver badge

Re: Sorry that handle is already taken

"This needs to be qualified by a statement that they've taken over a particular system"

Which is explained in the article.

"Can be used on any traffic signal site, anywhere in the world"

Read the article. What you've claimed is not reflected, overall, in what's published here.

C.

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Uhh flashing red would not be safe

As title, it'd confuse the HELL out of anyone not in merika

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Re: Uhh flashing red would not be safe

Confusing, maybe, but why unsafe? If you arrived at a light that was displaying an odd sequence I'd like to think you'd treat it as a stop signal, at least until you'd looked around you very carefully.

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Re: Uhh flashing red would not be safe

> As title, it'd confuse the HELL out of anyone not in merika

What? No! Although it's not part of the standard sequence for traffic lights in most of the world, flashing lights (OK, usually orange, but red ain't very different) are the standard danger signal for contruction works, road obstructions etc., so I reckon pretty much anyone allowed to drive a car would instinctively understand that it means "caution".

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Re: Uhh flashing red would not be safe

Have you been on any roads in Britain recently? Orange flashing lights might just as well be in the far infrared for all the notice most people take of them.

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Re: Uhh flashing red would not be safe

Yes, here in TN where monster thunderstorms occur, it is quite usual to have traffic lights flash.

But if I understand correctly (from conversation with colleagues), traffic lights are HARD WIRED to have a default state that is one direction "flashing yellow" (proceed with caution) and the other "flashing red" (STOP before proceeding). Especially remote ones...

I have seen it in a number of southern states, which is not so surprising when you think of the exciting weather...

If the hacks allowed the setting of green on both directions (a al Italian Job), that would be a problem. Otherwise everything else is probably not so dangerous, except of course how drivers behave...

I'm sure we have all sat at *that* traffic light in London that doesn't change....

P.

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One person doing this might not create a deadly situation... two however...

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Anonymous Coward

Traffic Light Pac Man

Cool!

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How long now some anarchic hacker takes a mini-drone

attaches a radio antenna, computer, mirror ball & sound system to it.

Then sets the drones on-board computer to hack into the nearest lights to flash them on and off in a disco style based on whatever tune is coming from the drones speakers.

This I can see someone attempting.

Very dangerous and irresponsible, lets hope for good sense.

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Re: How long now some anarchic hacker takes a mini-drone

How did you manage to get the plot for the next Batman movie?

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Anonymous Coward

Re: How long now some anarchic hacker takes a mini-drone

@drunk.smile: Or at least a decent sense of rhythm.

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Anonymous Coward

Network Distributed Credentials

This is another example where designers have chosen not to implement a proper credentials management system. Not surprising because writing one from scratch is difficult.

Even Unix hasn't got one of its own, with NIS seemingly having been replaced by SAMBA so as to leverage Microsoft Windows' Active Directory. SAMBA 4 will even do the job of an AD domain controller.

So either the Internet of Things and other embedded devices like traffic lights start using things like SAMBA and AD, or continue to have wide open default passwords. Having a private-ish network interface is not adequate.

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Re: Network Distributed Credentials

SAMBA 4 will even do some of the jobs of an AD domain controller

FTFY.

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Re: Network Distributed Credentials

Then you get things with hard wired "secret" passwords for the convenience of the makers support people.

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Unsuprising

I was asked to look at some of the back-end systems for this kind of stuff for a council a few years back. The issues I saw were very scary (even if I weren't under NDA I still wouldn't say as you'd think I'd made it up) and needless to say I chickened out of trying to actually experiment with anything. You can imagine the thoughts running through my head as I joined the massive trafic-jam on the way home. (I later found that it wasn't actually anything to do with me)

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USENIX

Am I the only one who read this as UNISEX?

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Re: USENIX

On El Reg? Yes, you're probablly the only one.

People here are more likely to parse "I feel horny" as "please install FreeBSD on my laptop".

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Re: USENIX

...when of course, as any fool knows, the correct way to ask for a BSD install is "I need some tail from a horny beast"

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Anonymous Coward

Almost did this myself

It was just a pedestrian crossing, but I have no reason the principle did not apply elsewhere.

In my vicinity, work was done on a pedestrian crossing. I walked past and noticed a phone number on the inside amongst some tech doc, so in the evening I called it with my modem (yes, it's long ago :) ). After a few attempts I had the right baudrate and I could just talk to the damn thing - at which point I exited because I may be way too curious for my own good, but I'm not a vandal.

It came to mind a couple of years later when people were war dialling - I wonder how many traffic lights they hit, because the number I found was just a local circuit.

Add some wireless link to that sort of security (i.e. none) and I am well able to believe they're hackable. However, AFAIK Central London lights are remote managed from one central location (that's how Ken Livingston was allegedly able to cause total weekend traffic mayhem when he was busy pushing through traffic limiting measures for London) so I wonder if that means an increased chance of being discovered, or a better range for someone once hacked...

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Coat

If they did that in Brum

they'd probably double the average traffic speed.

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Mushroom

Re: If they did that in Brum

Beat me to it you sod!

Now if we could remove the f**king buses that seem to stop every 50m, then we could triple the speed.

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Re:Buses

It's the bus stops they place (deliberately) opposite traffic islands that irk me. I once followed a bus from Horsefair for a mile, with about 10 stops where I had to sit behind and wait each time. Took 15 minutes. I could have walked faster (as could the bus passengers).

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Just a check

Reading that PDF is not going to make me a terrorist, is it ?

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All Sorts of Problems

Back in the 1980s when I was a student there were several traffic lights in the centre of Sheffiled that I could change to green on approach simply by pulsing the amateur radio transmitter in the car. Never worked out whether the RF was hitting the controller directly or affecting the induction loops in the road but it just goes to show that systems such as these have all kinds of potential vulnerabilities

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Re: All Sorts of Problems

Some very prevalent brands of temporary traffic lights in the UK use the same basic OOK now that those particular sets of lights in Sheffield used in the 1980s.

As such they don't care if it's AM/FM etc so long as the carrier wave is at about the right frequency. I wouldn't be surprised if it was just the presence of a cw that triggered the lights as you'd have to be pretty fluky to nail the OOK sequence.

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Need a green traffic light?

"Alternatively someone could create the ultimate car accessory; a radio that could green-light their entire trip.

IIRC, these device already exist in some places and are fitted to emergency vehicles. I don't remember if this was a production or experimental feature though.

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Anonymous Coward

Re: Need a green traffic light?

IIRC, these device already exist in some places and are fitted to emergency vehicles. I don't remember if this was a production or experimental feature though.

Fitted as standard to public transport buses in Switzerland, and even temporary lights are usually fitted with such a system.

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Go

Alternatively, just phase the lights --->

There used to be a time (I bet they've fucked it up now) on the A4, from Hounslow to the Chiswick roundabout, where if you got your timing right, you could sail through *every* light on green.

The trick was to start at a red light. And as you set of, accelerate steadily, until you got to 35. Then hold it (the speed limit was 40). If you did this, you'd see every light go green as you approached it. In off-peak conditions I could get from Hounslow to Kensington in 20 minutes.

It took a bit of nerve though, as it meant driving towards a red light at speed, and not slowing down. If you did, you'd start to fall behind, and eventually get caught.

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