Another one is how most 2g and 3g services (some SMS and voice connections) have known vulnerabilities. Unfortunately not just software security vulnerabilities, but also bad actors that can lease access within that system. That combination can allow for attacks within the underlying systems that make the target completely unaware for periods of time that their messages and voice calls are being intercepted, including 2 factor authentication content over SMS.
Another one is how most 2g and 3g services (some SMS and voice connections) have known vulnerabilities. Unfortunately not just software security vulnerabilities, but also bad actors that can lease access within that system. That combination can allow for attacks within the underlying systems that make the target completely unaware for periods of time that their messages and voice calls are being intercepted, including 2 factor authentication content over SMS.
Veritasium has a cool video about it. https://youtu.be/wVyu7NB7W6Y
If possible, it is best to not rely on SMS authentication for privacy.