The United States Department of Homeland Security (DHS) has flagged China, Russia, Iran, and Israel as the main nations exploiting vulnerabilities in the SS7 telecommunications protocol to spy on people within the country. According to details released by Senator Ron Wyden, these countries have been using the flaws to track physical movements, intercept calls and texts, and even deliver malware to mobile devices. These allegations, which highlight the misuse of SS7, mark a growing concern about global surveillance and the security of American communications.
SS7, a decades-old network protocol initially designed to route messages for roaming phone users, has been weaponized by malicious actors due to its inherent weaknesses. By leveraging SS7 access through legitimate telecom companies or operating their own networks, attackers can pinpoint user locations, intercept communications, and deploy spyware with nothing more than a phone number. The situation highlights the growing complexity of global espionage activities, causing concern for US authorities.
A global network of surveillance
A letter from the Department of Defense (DoD) in response to Senator Wyden’s inquiries revealed that in 2017, DHS identified the “primary countries” exploiting SS7, which included not only adversarial nations like China and Iran but also allies like Israel. The DHS presentation also mentioned other regions where telecom assets are used for spying, spanning Africa, Central and South America, and Europe.
The involvement of Israel, a US ally, draws particular attention. Despite being a close partner, Israel has been linked to aggressive espionage campaigns against American interests, according to intelligence reports. Additionally, Israel hosts a thriving surveillance technology industry, with firms like Circles—a company known for SS7 exploitation — now part of the infamous NSO Group. Reports indicate that governments around the globe, from Saudi Arabia to Guatemala, have allegedly employed SS7 capabilities to monitor individuals, amplifying the global nature of the issue.
The complexity of securing US networks
The US has faced significant challenges in safeguarding its telecommunications infrastructure against these vulnerabilities. SS7 attacks do not require conventional hacking but instead exploit fundamental design flaws in the protocol, making them harder to counteract. As recently as 2022 and 2023, reports of SS7-based surveillance against US personnel and critical locations such as Guam and Diego Garcia have emerged, though detailed responses from the DoD remain classified.
Efforts to address these risks have included security upgrades by private companies and partnerships with government entities. For example, the US Navy has piloted secure communication solutions with specialized networks in Guam. However, cybersecurity experts argue that addressing SS7 vulnerabilities requires a concerted effort across all telecom providers. The deployment of signalling firewalls, a key measure to prevent unauthorized access, has been slow and inconsistent despite the known risks.
A persistent threat with no easy fix
The enduring flaws in SS7 have sparked frustration among cybersecurity experts. The protocol’s vulnerabilities, discovered years ago, have yet to be comprehensively resolved. Analysts highlight that while firewalls can block many suspicious requests, more sophisticated actors continue to exploit the protocol for surveillance with relative ease. In some cases, governments and criminals alike have sent hundreds of tracking requests daily, illustrating the scale of the issue.
Despite the attention given to SS7 over the years, progress has been limited. Industry insiders lament that addressing the problem requires a multi-month effort at each telecom provider to implement proper security measures. While some efforts are underway, critics point out that these steps are dwarfed by the volume of discussions about SS7 vulnerabilities compared to actual solutions.
The revelations by Senator Wyden and the DoD highlight the critical need for a robust response to protect US citizens and government personnel from surveillance. However, with adversarial nations, allies, and even private entities leveraging SS7 flaws, the path to securing telecommunications networks remains fraught with challenges. As the US grapples with this complex issue, the wider implications for global privacy and security continue to unfold.
