Typical severity: High. An attacker, with control of a Cellular Rogue Base Station or through cooperation with a Malicious Mobile Network Operator can force the mobile device (e.g., the retransmission device) to use no encryption (A5/0 mode) or to use easily breakable encryption (A5/1 or A5/2 mode).
Use of hardened baseband firmware on retransmission device to detect and prevent the use of weak cellular encryption. | Monitor cellular RF interface to detect the usage of weaker-than-expected cellular encryption.