The advisory came on August 1 from DHS' Federal Emergency Alert Agency (FEMA). Cybersecurity experts Ken Pyle found out about the vulnerabilities. 

FEMA said the EAS national test in 2021 was very similar to regular monthly tests typically originated by state authorities. 

During the test, radios and televisions across the country interrupted normal programming to play the EAS test message in English or Spanish. 

"The EAS national test in 2021 was very similar to regular monthly tests typically originated by state authorities. During the test, radios and televisions across the country interrupted normal programming to play the EAS test message in English or Spanish," reports FEMA.

EAS is a U.S. national public warning system that allows state authorities to send out information in less than 10 minutes if there's an emergency. These warnings can interrupt TV and radio to show emergency alert information. 

Information about the bugs has not been disclosed to prevent threat actors from exploiting them, but we can expect the details publicly soon as a proof-of-concept at the DEF CON conference going to take place in Las Vegas next week. 

Basically, the flaws are public knowledge and will be shown to a large audience in the following weeks. 

To control the vulnerability, users are advised to update the EAS devices to the latest software versions, use a firewall to secure them, and keep an eye on audit and review logs for signs of any suspicious access (unauthorised). 

"The testing process is designed to evaluate the effectiveness of the IPAWS Open Platform for Emergency Networks and assess the operational readiness of the infrastructure for distribution of a national message and determine whether technological improvements are needed," reports FEMA.