5 ms·

> stingrays can force phones to downgrade to 2G, a less secure protocol, and tell the phone to use either no encryption or use a weak encryption that can be cra

> stingrays can force phones to downgrade to 2G, a less secure protocol, and tell the phone to use either no encryption or use a weak encryption that can be cracked. Can android, iOS, or an open phone os prevent 2g communication?

xxpor 6y ago
On my phone (Galaxy Note 10), there's a toggle to allow 2G or not in the mobile network settings. No debug code needed or anything like that.
shakna 6y ago
It happens within the OS for the baseband processor, not within the OS of the actual phone. Unsurprisingly, the details of how the baseband processor work are a highly guarded secret, and trying to reverse engineer anything around it will end up with a heft lawsuit thrown at you.
- jacquesm 6y ago
  > trying to reverse engineer anything around it will end up with a heft lawsuit thrown at you. Is there an example of that? I can't imagine how reverse engineering anything would get a hefty lawsuit thrown at you. Maybe if you were to publish the results with your name under it, but just the act of reverse engineering?
- kawsper 6y ago
  These low-level systems can be good attack vectors, on our computer systems if you can attack the BIOS (Intel ME or AMD PSP) it doesn't matter much what defenses the operating system has. Luckily, most of our computers aren't easily remotely connectable, but phone modems are another story.
- jessaustin 6y ago
  Presumably the creators of these devices have done at least some of that reverse engineering?
pas 6y ago
This is probably something that the baseband radio processor decides. Depending on the firmware/software on the chip the host OS might be able to instruct it to don't ever downgrade to 2G.
jdefr89 6y ago
Hey, I used to briefly work on the device in question. It’s capabilities go far beyond just downgrading cellular service. I obviously can’t say much more about it but I am a huge proponent of creating strong laws regarding who can use such a device and when. Putting such devices in the hands of low level law enforcement officers to use against their communities for trivial reasons can only turn out poorly.
- thimkerbell 6y ago
  jdefr, can it change what I read?
boring_twenties 6y ago
On Android, enter \#\#4636#\#\ in the dialer. Then select "LTE only." (This will prevent 3G as well as 2G) edit: You gotta be kidding me with this formatting. Replace backslashes with asterisks.
- function_seven 6y ago
  My apologies if this comes out garbled. Trying something... ∗#∗#4636#∗#∗
  - boring_twenties 6y ago
    How?
    - edflsafoiewq 6y ago
      ∗=U+2217
  - ideals 6y ago
    Before I entered a random string into my phone I did a quick search which pulls up a bunch of other dialer commands for Android. It's pretty interesting https://android.stackexchange.com/questions/1468/do-you-know-other-android-keypad-commands-dialer-codes https://android.stackexchange.com/questions/1468/do-you-know...
- deleted 6y ago
  [deleted]
- godelski 6y ago
  That's because it is for MarkDown. So you can do things like this. But you can do * this * and it is fine. The difference is spacing.
  - edflsafoiewq 6y ago
    In normal Markdown you can escape with \ but it doesn't work on HN for some reason.
WarOnPrivacy 6y ago
>Can android, iOS, or an open phone os prevent 2g communication? Some android installs can turn off 2g here: Settings -> Mobile Networks -> Network Mode However - 2G & 3g networks appear to be going away. https://1ot.mobi/resources/blog/a-complete-overview-of-2g-3g-sunsets https://1ot.mobi/resources/blog/a-complete-overview-of-2g-3g... AT&T killed 2g in 2017 https://www.pcmag.com/news/att-kills-2g-cutting-off-original-iphone https://www.pcmag.com/news/att-kills-2g-cutting-off-original... T-Mobile is in the process of turning off 2g https://www.alarmgrid.com/blog/t-mobile-and-rogers-2g-networks-to-shut-down-at-end-of-2020 https://www.alarmgrid.com/blog/t-mobile-and-rogers-2g-networ...
deleted 6y ago
[deleted]
fulafel 6y ago
They could but they don't, and it's been known all along that these downgrade attacks are devastating to security and very practical. Complicity?
- Spooky23 6y ago
  Nah. People use legacy devices for a long time. The 2G modem installed in 2006 to control a highway sign works just fine, and won’t get touched until they turn it off.
  - fulafel 6y ago
    the thing being questioned was behaviour of new phones.
sudosysgen 6y ago
On Android, on most phones you can do ##4636##, then get access to the service menu and configure the modem to act how you want it to.
- deleted 6y ago
  [deleted]
myself248 6y ago
Sadly, the only baseband I'm aware of with open firmware is, itself, a 2g chip: https://www.freecalypso.org/ https://www.freecalypso.org/ Nothing newer gives you any sort of control, as far as I know. Would love to learn more.

xxpor 6y ago

On my phone (Galaxy Note 10), there's a toggle to allow 2G or not in the mobile network settings. No debug code needed or anything like that.

shakna 6y ago

It happens within the OS for the baseband processor, not within the OS of the actual phone. Unsurprisingly, the details of how the baseband processor work are a highly guarded secret, and trying to reverse engineer anything around it will end up with a heft lawsuit thrown at you.

jacquesm 6y ago
> trying to reverse engineer anything around it will end up with a heft lawsuit thrown at you. Is there an example of that? I can't imagine how reverse engineering anything would get a hefty lawsuit thrown at you. Maybe if you were to publish the results with your name under it, but just the act of reverse engineering?
kawsper 6y ago
These low-level systems can be good attack vectors, on our computer systems if you can attack the BIOS (Intel ME or AMD PSP) it doesn't matter much what defenses the operating system has. Luckily, most of our computers aren't easily remotely connectable, but phone modems are another story.
jessaustin 6y ago
Presumably the creators of these devices have done at least some of that reverse engineering?

pas 6y ago

This is probably something that the baseband radio processor decides. Depending on the firmware/software on the chip the host OS might be able to instruct it to don't ever downgrade to 2G.

jdefr89 6y ago

Hey, I used to briefly work on the device in question. It’s capabilities go far beyond just downgrading cellular service. I obviously can’t say much more about it but I am a huge proponent of creating strong laws regarding who can use such a device and when. Putting such devices in the hands of low level law enforcement officers to use against their communities for trivial reasons can only turn out poorly.

thimkerbell 6y ago
jdefr, can it change what I read?

boring_twenties 6y ago

On Android, enter \#\#4636#\#\ in the dialer. Then select "LTE only." (This will prevent 3G as well as 2G) edit: You gotta be kidding me with this formatting. Replace backslashes with asterisks.

function_seven 6y ago
My apologies if this comes out garbled. Trying something... ∗#∗#4636#∗#∗
- boring_twenties 6y ago
  How?
  - edflsafoiewq 6y ago
    ∗=U+2217
- ideals 6y ago
  Before I entered a random string into my phone I did a quick search which pulls up a bunch of other dialer commands for Android. It's pretty interesting https://android.stackexchange.com/questions/1468/do-you-know-other-android-keypad-commands-dialer-codes https://android.stackexchange.com/questions/1468/do-you-know...
deleted 6y ago
[deleted]
godelski 6y ago
That's because it is for MarkDown. So you can do things like this. But you can do * this * and it is fine. The difference is spacing.
- edflsafoiewq 6y ago
  In normal Markdown you can escape with \ but it doesn't work on HN for some reason.

WarOnPrivacy 6y ago

>Can android, iOS, or an open phone os prevent 2g communication? Some android installs can turn off 2g here: Settings -> Mobile Networks -> Network Mode However - 2G & 3g networks appear to be going away. https://1ot.mobi/resources/blog/a-complete-overview-of-2g-3g-sunsets https://1ot.mobi/resources/blog/a-complete-overview-of-2g-3g... AT&T killed 2g in 2017 https://www.pcmag.com/news/att-kills-2g-cutting-off-original-iphone https://www.pcmag.com/news/att-kills-2g-cutting-off-original... T-Mobile is in the process of turning off 2g https://www.alarmgrid.com/blog/t-mobile-and-rogers-2g-networks-to-shut-down-at-end-of-2020 https://www.alarmgrid.com/blog/t-mobile-and-rogers-2g-networ...

deleted 6y ago

[deleted]

fulafel 6y ago

They could but they don't, and it's been known all along that these downgrade attacks are devastating to security and very practical. Complicity?

Spooky23 6y ago
Nah. People use legacy devices for a long time. The 2G modem installed in 2006 to control a highway sign works just fine, and won’t get touched until they turn it off.
- fulafel 6y ago
  the thing being questioned was behaviour of new phones.

sudosysgen 6y ago

On Android, on most phones you can do ##4636##, then get access to the service menu and configure the modem to act how you want it to.

deleted 6y ago
[deleted]

myself248 6y ago

Sadly, the only baseband I'm aware of with open firmware is, itself, a 2g chip: https://www.freecalypso.org/ https://www.freecalypso.org/ Nothing newer gives you any sort of control, as far as I know. Would love to learn more.