Theft prevention system can be exploited to block your new phone or disable home alarms

The system built to stop stolen phones from working could actually be turned against you. Michigan State University researchers just found six security flaws in the lost and stolen device reporting process, the same one carriers use to blacklist phones by their unique IMEI number.

Turns out an attacker doesn’t need to steal your phone to block it. They just need to exploit weak identity checks in how carriers verify who’s filing the report.

How bad could this actually get?

According to the two proof-of-concept attacks the team pulled off on live 4G and 5G networks. One, called Zero-Day Flagship Phone Ambush, showed how someone could grab a device’s IMEI before it even launches and get it wrongly flagged as stolen. Researchers proved this using a Samsung Galaxy Z Fold 7, blocking it from cellular service before its public release.

The other attack, called Home Security System Freezing, targets the cellular backup connection many home alarm systems rely on when Wi-Fi goes down. Researchers found two major home security providers, covering more than 41% of the US market, use vulnerable cellular modem chipsets. That backup link is exactly what’s supposed to keep your alarm talking to monitoring centers during an emergency.

So what’s next?

The researchers aren’t calling for the reporting system to be scrapped. They just want it to be locked down better. Their proposed fixes include stronger identity verification for anyone who is filing a lost device report, along with tighter security around the GSMA’s cross-carrier blacklist database. The GSMA has already acknowledged the findings and has passed them along to its device security group.

This study was given the Best Paper Award at MobiSys 2026, the top conference for mobile systems research, so it’s not some fringe theory. This is a real gap that carriers now need to close.