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by janwillemb 245 days ago
It is about a company, First Wap, that makes it possible to track individuals. Their USP is a piece of software that operates at phone network level and uses the fact that phone companies still support an old protocol, Signalling System 7:

> Phone networks need to know where users are in order to route text messages and phone calls. Operators exchange signalling messages to request, and respond with, user location information. The existence of these signalling messages is not in itself a vulnerability. The issue is rather that networks process commands, such as location requests, from other networks, without being able to verify who is actually sending them and for what purpose.

> These signalling messages are never seen on a user’s phone. They are sent and received by “Global Titles” (GTs), phone numbers that represent nodes in a network but are not assigned to subscribers.
2 comments
overfeed 244 days ago
> The issue is rather that networks process commands, such as location requests, from other networks, without being able to verify who is actually sending them and for what purpose

'Fun' fact: "other networks" includes all foreign networks with a roaming partnership. It's possible to abuse SS7 to track people across borders, from half the world away.

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foolfoolz 244 days ago
it’s more than that. it’s any device that can present itself as a possible base station. this is how trumps lawyer was caught in a place he claimed to not be: https://www.reuters.com/article/world/special-counsel-has-ev...

this also helped confirm the identity of the 2022 killer in idaho https://en.wikipedia.org/wiki/2022_University_of_Idaho_murde...

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mercora 244 days ago
> it’s more than that. it’s any device that can present itself as a possible base station.

can you elaborate on this a bit? what devices are able to to present themselves as possible base stations? do i need any form of entitlement to participate in the network or not? From past encounters with SS7 and its, uhm, capabilities, it seemed the hardest part would be getting access to the network, albeit not hard really, it sounds like you were hinting at possibly gaining access by participating in the network without any official entitlement, by posing as a base station.

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rsync 244 days ago
I believe he is referring to femtocells which have (are ?) given freely to end users who need cellular signal boosting, etc.

Many of these femtocells, historically, could be trivially altered or updated to participate as literal peers on SS7.

I haven't looked into this for many years but there was a time when operating a certain femtocell granted the owner an enormous amount of leverage on the global telecom network ...

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beached_whale 245 days ago
I assumed it was the telecoms just selling the data about their subscribers. https://www.telecomstechnews.com/news/fcc-fines-major-telcos...
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pkulak 244 days ago
Why not both?
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beached_whale 244 days ago
One would hope the selling is illegal and did more than just fine the companies.
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