Relying on SMS for two-factor authentication is problematic because it is often the only available option for important accounts.

“Unfortunately, yes, it's not only the default but in some cases it is the only available option and sometimes that can even be for accounts that should be treated with the utmost of care like a bank account.”

Users should utilize authenticator apps or hardware tokens instead of SMS for two-factor authentication to avoid interception.

“If possible, choose alternatives to SMS based two-factor authentication. So messages can't be intercepted. Use an Authenticator app or hardware tokens.”