Briefly: look into sim swapping, which is the most obvious, day to day risk.
Then there’s SS7 and how inherently trusting the whole system is.
Then depending on where you are, some mobile networks still have terrible link encryption (were talking so bad a normal laptop is enough these days to break it on the fly). Granted, this is rare these days, in part thanks to the efforts of Karsten Knohl, SRLabs and other security researchers who did a lot to shine a light on this and SS7
This is becoming less of an issue as US Mobile has anti-SIM-hijacking protection; hopefully other carriers will follow suit. Of course, the carriers themselves can still read your msgs, but so can WhatsApp, probably (despite their claims to the contrary).
[citation needed] on the second half
A big feature of sms is that it’s not encrypted. Every tower that recieves the message is trusted to forward it unaltered. This is one attack avenue.
https://www.helpnetsecurity.com/2020/11/12/sms-voice-mfa/
Things like the following are generally recommended though Microsoft recommends using their app. https://www.yubico.com/
I should have clarified that sms 2fa is insecure not 2fa.
Okay that makes sense. Yes sms is insecure, not 2fa.
Briefly: look into sim swapping, which is the most obvious, day to day risk.
Then there’s SS7 and how inherently trusting the whole system is.
Then depending on where you are, some mobile networks still have terrible link encryption (were talking so bad a normal laptop is enough these days to break it on the fly). Granted, this is rare these days, in part thanks to the efforts of Karsten Knohl, SRLabs and other security researchers who did a lot to shine a light on this and SS7
Not sure how up to date it still is, but https://gsmmap.srlabs.de/ shows how unequal networks are.
This is becoming less of an issue as US Mobile has anti-SIM-hijacking protection; hopefully other carriers will follow suit. Of course, the carriers themselves can still read your msgs, but so can WhatsApp, probably (despite their claims to the contrary).
That’s all sms though, not 2fa in general.
All valid points and good information within that scope.
Are you an LLM?
It’s been edited, bud. Originally it said that 2fa in general is insecure.
The edit icon is a bit not-obvious in Voyager…
And I can’t view the original text.
Edit: Speeling on a phone is hard (read: annyoing)
I don’t think the original text before edits is viewable by anyone other than possibly instance admins.
there used to be the trick to click “view source” to do so. worked for anyone on any client a couple hours back in time.
but that was fixed long ago (years?)