Authentication flaw

The Wireless Emergency Alerts (WEA) protocol allows remote attackers to spoof a Presidential Alert because cryptographic authentication is not used, as demonstrated by MessageIdentifier 4370 in LTE System Information Block 12 (aka SIB12). NOTE: testing inside an RF-isolated shield box suggested that all LTE phones are affected by design (e.g., use of Android versus iOS does not matter); testing in an open RF environment is, of course, contraindicated.