SS7 Security Flaws Leave US Telecom Networks Open to Attack

The U.S. Department of Homeland Security (DHS) has identified nations actively exploiting vulnerabilities in telecommunications networks to conduct espionage within the United States. According to Senator Ron Wyden, the list includes China, Iran, and Israel, which leverage weaknesses in the SS7 communication protocol to track movements, intercept calls, and access text messages.

The security flaws of SS7 have long been a subject of concern. Previously, CISA reported numerous attacks exploiting SS7 vulnerabilities in recent years. A newly released document from the U.S. Department of Defense (DoD) provides further specificity, attributing these attacks to the aforementioned nations.

The document reveals that in 2017, DHS presented a report outlining the risks of SS7 and naming key countries using third-party telecommunications systems to target U.S. subscribers. The list also included nations from Africa, Central and South America, Europe, and the Middle East.

Technology companies confirm the severity of the issue, citing evidence of malicious activity linked to SS7 originating from these countries. Despite the U.S.’s alliance with Israel, intelligence agencies noted aggressive espionage by the country as early as 2014, including actions by Israeli companies exploiting SS7 vulnerabilities.

Initially designed to facilitate message routing in roaming, SS7 has become a tool not only for governments but also for commercial entities and criminals. Accessing the system enables attackers to track individuals’ locations and intercept communications with nothing more than a phone number. The vulnerability is also exploited to deliver malware to target devices.

The inadequate protection provided by telecom operators is a growing concern. The DoD has confirmed that all U.S. telecommunications networks remain susceptible to attacks via SS7 and its updated counterpart, Diameter. However, independent audit results of these networks are unavailable for review due to legal constraints.

Criticism has been directed at the slow progress in addressing these vulnerabilities. Experts emphasize that effective protection requires extensive configuration and overhaul of telecommunications infrastructure. Despite efforts by some nations, the pace of resolving these issues remains sluggish.

Amid ongoing threats, the U.S. Navy has begun deploying the Cape secure communications network in pilot projects. Nonetheless, the danger persists, as exploiting SS7 requires only basic access to network systems. Telecom operators and representatives from the implicated nations have declined to comment. The matter remains unresolved, and SS7 continues to serve as a critical vector for global espionage and cyberattacks.