5 ms·

I can tell you traffic lights are extremely insecure. Last month there was a traffic light that was turned the wrong way, such that it was impossible to tell if

I can tell you traffic lights are extremely insecure. Last month there was a traffic light that was turned the wrong way, such that it was impossible to tell if the light was green. So I climbed the poll and turned it to the right direction. Another fellow pedastrian thanked me. A bad actor could do anything from a DOS (positioning it the wrong direction) to tampering with the bulbs (for example swapping out all the greens with reds). The reason most society doesn't collapse is because we assume most people are good actors. Unfortunately once your device is hooked up to the internet you vastly increase the odds of dealing with bad actors and have to spend more time and money securing against bad actors.

brokenmachine 7y ago
All the traffic lights here in Australia are honking great big metal poles that you'd need some serious equipment to reposition. Swapping bulbs would be a big operation too. What country are you in that has rotatable traffic lights?
- johannes1234321 7y ago
  Even if the traffic lights can't be rotsteted it's relatively trivial for an bad actor to break it in some way and hanging up your permanent green light at night and then watch the chaos. As gp said: The amount of such bad actors is low. And gains from an individual hack are low and there's a chance of getting caught.
  - Waterluvian 7y ago
    "Relatively trivial" must be relative. Traffic lights where I am require a cherry picker in the intersection to get at. This is like hacking servers. If you can get all the way to physical access with the device, of course it's exploitable. But that doesn't actually say a lot about how secure something is. I imagine the quality of the lights around the world differ. If you can climb up and adjust it, these aren't the kinds of lights I'm thinking of.
    - jdavis703 7y ago
      Here's some photo evidence from Palo Alto, CA, USA: https://imgur.com/a/NxmphG6 https://imgur.com/a/NxmphG6. Note how both lights are parallel when they should be perpendicular.
      - Waterluvian 7y ago
        Ah yeah I see now. Very cool. Very different! Ours generally look like this: http://i.imgur.com/m9fAs.jpg http://i.imgur.com/m9fAs.jpg So you'd need some equipment to do anything to them. And that equipment would have to basically shut down the intersection. So do it at 4am and hope that nobody drives by for the half hour you're there.
    - toast0 7y ago
      > Traffic lights where I am require a cherry picker in the intersection to get at. How hard is it to get a cherry picker? (Check your local tool/construction rental place) What about if you climb on top of a van, or a box truck?
- jdavis703 7y ago
  I'm in the USA. This particular incident happened in Washington, DC. I also saw a driver do this once in Palo Alto in Silicon Valley. Anyways, even if lights are too big to climb up you can put on a yellow vest and get a flashing light on your van and people wouldn't really think twice. Here's some photo evidence from Palo Alto, CA, USA: https://imgur.com/a/NxmphG6 https://imgur.com/a/NxmphG6
  - brokenmachine 7y ago
    Wow, yeah those are super flimsy. Looks like some DIY job with plumbing pipes! Traffic lights here are nothing like that.
    - jdavis703 7y ago
      I hopped on Google Street view near the central core of Sydney, and it looks like at least in certain areas you all also have lights like that are close to the ground and easily accessible. I'm guessing in more suburban or rural areas the signals are higher up (which makes them easier to see from a distance while driving faster).
      - brokenmachine 7y ago
        Can you share a link to one? All the ones I remember look pretty damn solid.
henvic 7y ago
I live near a big avenue that has 12 lanes (6 for each direction). There are two local lanes (that you can enter or exit only on a few places). It has been this way probably for longer than I'm alive (30 years). There is a huge traffic light for the central lanes with a visual timer (like all others in this avenue: green horizontal lines that fade one by one when the signal is closing soon) and a smaller one for the local south lanes on a given crossing. After some road paving, pedestrian crossings were made accessible, but for some stupid reason changed the behavior of the local traffic to a deadly combination. The speed limit is 60km/h for both central and local lanes (but people drive from anything between 50-100km/h). Previously for 30+ years: everything turned green/red at the very same time. Since around some date before 1 January: central lanes turn green first. Smaller traffic light for the local lanes turns green after 10 seconds. Local lanes turn red a few seconds after the central too. In some places, it might create an incentive for you to swift to local and back (while hitting the gas pedal) after 30s-1min if you see traffic ahead and that you can't make it in the central lanes - not sure if I consider this a feature or a safety risk. First time I passed by after the change I didn't stop (5.a.m. new year's eve) because I was watching the central lane semaphore and it was too late when I noticed they changed it. A second time, I had to hit the breaks. During the first weeks after the changes, I saw a dozen or more cars either running the red light without stopping or after waiting for the [central] lane bright traffic lights go green. Six months afterward, a reckless military driver killed a disabled woman in a wheelchair nearby. Probably unrelated but I'd be surprised if a related road design fault played a role.
akira2501 7y ago
> I can tell you traffic lights are extremely insecure. All municipal infrastructure tends to be. It's usually implemented to a cost and security considerations are completely absent. You can bet that in any given city, all those street light control cabinets are keyed alike and the city has no true idea who has keys and who doesn't. This exact problem applies to so many domains it's literally for lack of effort that they haven't been exploited yet.
- distant_hat 7y ago
  In India I found that in Bangalore (a city with far better infrastructure than most other), for a lot of intersections the traffic lights are toggle switches that some cop flicks on and off every so often. There is no lock on the switch cabinet.
- dotancohen 7y ago
  All those cabinets use the same key across cities as well! Otherwise FEMA and other services would be unable to function. For the same reason all LEO handcuffs use the same key, so that any officer could release any handcuffed individual. Edit: Some googling for links let me to this video, which seems relevant: I'll Let Myself In: Tactics of Physical Pen Testers https://www.youtube.com/watch?v=rnmcRTnTNC8 https://www.youtube.com/watch?v=rnmcRTnTNC8
microcolonel 7y ago
> tampering with the bulbs (for example swapping out all the greens with reds). Traffic authorities use coloured bulbs where you are? Weird. Where I am, as far as I'm aware the colours always come from a gel in front of the lamp. Furthermore, the red lamp holder is larger than the green and amber ones.
- isostatic 7y ago
  Don't you have LED lights?
  - microcolonel 7y ago
    I think they still use gels on white LEDs for many of them. I've had a look at a few that at least did that. It's possible they've switched to dedicated colour phosphors, or that the majority of them have been that way for a while. I think many of the lights here are also retrofits from incandescent traffic lights.
asdff 7y ago
It's pretty pragmatic to take a 'wait and see' approach to dealing with bad actors. You start doing that in your town and there will be some changes once budget adjustments are made. LA had a problem with people tagging signs on the freeway, so now many are wrapped in razor wire.

brokenmachine 7y ago

All the traffic lights here in Australia are honking great big metal poles that you'd need some serious equipment to reposition. Swapping bulbs would be a big operation too. What country are you in that has rotatable traffic lights?

johannes1234321 7y ago
Even if the traffic lights can't be rotsteted it's relatively trivial for an bad actor to break it in some way and hanging up your permanent green light at night and then watch the chaos. As gp said: The amount of such bad actors is low. And gains from an individual hack are low and there's a chance of getting caught.
- Waterluvian 7y ago
  "Relatively trivial" must be relative. Traffic lights where I am require a cherry picker in the intersection to get at. This is like hacking servers. If you can get all the way to physical access with the device, of course it's exploitable. But that doesn't actually say a lot about how secure something is. I imagine the quality of the lights around the world differ. If you can climb up and adjust it, these aren't the kinds of lights I'm thinking of.
  - jdavis703 7y ago
    Here's some photo evidence from Palo Alto, CA, USA: https://imgur.com/a/NxmphG6 https://imgur.com/a/NxmphG6. Note how both lights are parallel when they should be perpendicular.
    - Waterluvian 7y ago
      Ah yeah I see now. Very cool. Very different! Ours generally look like this: http://i.imgur.com/m9fAs.jpg http://i.imgur.com/m9fAs.jpg So you'd need some equipment to do anything to them. And that equipment would have to basically shut down the intersection. So do it at 4am and hope that nobody drives by for the half hour you're there.
  - toast0 7y ago
    > Traffic lights where I am require a cherry picker in the intersection to get at. How hard is it to get a cherry picker? (Check your local tool/construction rental place) What about if you climb on top of a van, or a box truck?
jdavis703 7y ago
I'm in the USA. This particular incident happened in Washington, DC. I also saw a driver do this once in Palo Alto in Silicon Valley. Anyways, even if lights are too big to climb up you can put on a yellow vest and get a flashing light on your van and people wouldn't really think twice. Here's some photo evidence from Palo Alto, CA, USA: https://imgur.com/a/NxmphG6 https://imgur.com/a/NxmphG6
- brokenmachine 7y ago
  Wow, yeah those are super flimsy. Looks like some DIY job with plumbing pipes! Traffic lights here are nothing like that.
  - jdavis703 7y ago
    I hopped on Google Street view near the central core of Sydney, and it looks like at least in certain areas you all also have lights like that are close to the ground and easily accessible. I'm guessing in more suburban or rural areas the signals are higher up (which makes them easier to see from a distance while driving faster).
    - brokenmachine 7y ago
      Can you share a link to one? All the ones I remember look pretty damn solid.

henvic 7y ago

I live near a big avenue that has 12 lanes (6 for each direction). There are two local lanes (that you can enter or exit only on a few places). It has been this way probably for longer than I'm alive (30 years). There is a huge traffic light for the central lanes with a visual timer (like all others in this avenue: green horizontal lines that fade one by one when the signal is closing soon) and a smaller one for the local south lanes on a given crossing. After some road paving, pedestrian crossings were made accessible, but for some stupid reason changed the behavior of the local traffic to a deadly combination. The speed limit is 60km/h for both central and local lanes (but people drive from anything between 50-100km/h). Previously for 30+ years: everything turned green/red at the very same time. Since around some date before 1 January: central lanes turn green first. Smaller traffic light for the local lanes turns green after 10 seconds. Local lanes turn red a few seconds after the central too. In some places, it might create an incentive for you to swift to local and back (while hitting the gas pedal) after 30s-1min if you see traffic ahead and that you can't make it in the central lanes - not sure if I consider this a feature or a safety risk. First time I passed by after the change I didn't stop (5.a.m. new year's eve) because I was watching the central lane semaphore and it was too late when I noticed they changed it. A second time, I had to hit the breaks. During the first weeks after the changes, I saw a dozen or more cars either running the red light without stopping or after waiting for the [central] lane bright traffic lights go green. Six months afterward, a reckless military driver killed a disabled woman in a wheelchair nearby. Probably unrelated but I'd be surprised if a related road design fault played a role.

akira2501 7y ago

> I can tell you traffic lights are extremely insecure. All municipal infrastructure tends to be. It's usually implemented to a cost and security considerations are completely absent. You can bet that in any given city, all those street light control cabinets are keyed alike and the city has no true idea who has keys and who doesn't. This exact problem applies to so many domains it's literally for lack of effort that they haven't been exploited yet.

distant_hat 7y ago
In India I found that in Bangalore (a city with far better infrastructure than most other), for a lot of intersections the traffic lights are toggle switches that some cop flicks on and off every so often. There is no lock on the switch cabinet.
dotancohen 7y ago
All those cabinets use the same key across cities as well! Otherwise FEMA and other services would be unable to function. For the same reason all LEO handcuffs use the same key, so that any officer could release any handcuffed individual. Edit: Some googling for links let me to this video, which seems relevant: I'll Let Myself In: Tactics of Physical Pen Testers https://www.youtube.com/watch?v=rnmcRTnTNC8 https://www.youtube.com/watch?v=rnmcRTnTNC8

microcolonel 7y ago

> tampering with the bulbs (for example swapping out all the greens with reds). Traffic authorities use coloured bulbs where you are? Weird. Where I am, as far as I'm aware the colours always come from a gel in front of the lamp. Furthermore, the red lamp holder is larger than the green and amber ones.

isostatic 7y ago
Don't you have LED lights?
- microcolonel 7y ago
  I think they still use gels on white LEDs for many of them. I've had a look at a few that at least did that. It's possible they've switched to dedicated colour phosphors, or that the majority of them have been that way for a while. I think many of the lights here are also retrofits from incandescent traffic lights.

asdff 7y ago

It's pretty pragmatic to take a 'wait and see' approach to dealing with bad actors. You start doing that in your town and there will be some changes once budget adjustments are made. LA had a problem with people tagging signs on the freeway, so now many are wrapped in razor wire.