STIR/SHAKEN has an exception for calls passing through TDM trunks, which don't support it. This created a small industry for passing spam calls through TDM trunks. Such calls can trivially have their caller ID spoofed.
STIR/SHAKEN has an exception for calls passing through TDM trunks, which don't support it. This created a small industry for passing spam calls through TDM trunks. Such calls can trivially have their caller ID spoofed.
Phone companies used to be monopolies, in Europe they were owned by the government as a public service. But when they become profitable politicians betrayed their citizens and sold them. Nowadays, phone companies are a source of scams, spam and everything wrong with big corporations. And all that profits are now private instead of helping to fund the country.
Why are those non-STIR/SHAKEN TDM trunks serving as transit trunks (non-terminating), rather than terminal-only trunks? Seems a pretty obvious hole to close.
Slides: https://media.defcon.org/DEF%20CON%2033/DEF%20CON%2033%20pre...
Video recording: somewhere