New Flaws In 4G, 5G Allow Attackers To Intercept Calls and Track Phone Locations

An anonymous reader quotes a report from TechCrunch: A group of academics have found three new security flaws in 4G and 5G, which they say can be used to intercept phone calls and track the locations of cell phone users. The findings are said to be the first time vulnerabilities have affected both 4G and the incoming 5G standard, which promises faster speeds and better security, particularly against law enforcement use of cell site simulators, known as 'stingrays.' But the researchers say that their new attacks can defeat newer protections that were believed to make it more difficult to snoop on phone users. [Rafiul Hussain, one of the co-authors of the paper, along with Ninghui Li and Elisa Bertino at Purdue University, and Mitziu Echeverria and Omar Chowdhury at the University of Iowa are set to reveal their findings at the Network and Distributed System Security Symposium in San Diego on Tuesday.

The paper, seen by TechCrunch prior to the talk, details the attacks: the first is Torpedo, which exploits a weakness in the paging protocol that carriers use to notify a phone before a call or text message comes through. The researchers found that several phone calls placed and cancelled in a short period can trigger a paging message without alerting the target device to an incoming call, which an attacker can use to track a victim's location. Knowing the victim's paging occasion also lets an attacker hijack the paging channel and inject or deny paging messages, by spoofing messages like Amber alerts or blocking messages altogether, the researchers say. Torpedo opens the door to two other attacks: Piercer, which the researchers say allows an attacker to determine an international mobile subscriber identity (IMSI) on the 4G network; and the aptly named IMSI-Cracking attack, which can brute force an IMSI number in both 4G and 5G networks, where IMSI numbers are encrypted. AT&T, Verizon, Sprint and T-Mobile are all affected by Torpedo, 'and the attacks can be carried out with radio equipment costing as little as $200,' the report adds. One U.S. network is reportedly vulnerable to the Piercer attack, but the researcher wouldn't name which one.

Read more of this story at Slashdot.