Every call you make, every text you send, zipping through a global network that’s been the backbone of telecom for decades. Now imagine that same network, built on trust in a simpler era, being exploited to track your exact location—down to the street you’re standing on—by someone with no business knowing. This is the stark reality of the Signaling System No. 7 (SS7) protocol, a 1970s technology still powering billions of daily communications in 2025. While SS7 enables seamless roaming and call setup, its outdated design leaves it wide open to abuse, especially for location tracking. As 5G networks expand and IoT devices flood the ecosystem, the stakes for SS7 security have never been higher. Cyber-criminals, state actors, and even rogue insiders can exploit SS7 to invade privacy, steal data, or worse.

For IT professionals, cybersecurity experts, and telecom engineers, understanding and securing SS7 isn’t just a technical challenge—it’s a race against time to protect the trust that underpins global communication. This comprehensive guide dives into SS7 security, unpacking its vulnerabilities, sharing real-world case studies, and equipping you with practical tools to lock down your network.

Table of Contents

What Is SS7 and Why Does SS7 Security Matter?

SS7, or Signaling System No. 7, is a set of telephony protocols that enables communication between network elements, such as setting up calls, routing SMS, and managing roaming. Developed in 1975, SS7 was designed for a closed, trusted ecosystem where only telecom operators had access. Fast-forward to 2025, and the landscape has changed dramatically. The proliferation of mobile devices, VoIP providers, and third-party services has expanded SS7 access, creating new vulnerabilities.

Why SS7 Security Matters:

Location Tracking Risks: Attackers can exploit SS7 to pinpoint a device’s location using commands like Send Routing Information (SRI) and Provide Subscriber Information (PSI). In 2014, German researcher Karsten Nohl demonstrated how a phone’s location could be tracked with just its number.
Data Interception: SS7 flaws allow hackers to intercept SMS and calls, compromising sensitive data like two-factor authentication (2FA) codes. A 2017 bank heist in Germany saw criminals use SS7 to steal SMS-based transaction codes.
Global Reach: With SS7 connecting networks worldwide, a single breach can affect subscribers across countries, making SS7 security a universal concern.

For telecom engineers, ignoring SS7 vulnerabilities is like leaving the backdoor of a bank vault wide open. As 2G and 3G networks persist alongside 4G and 5G, securing SS7 remains critical.

How Does SS7-Based Location Tracking Work?

To understand SS7 security, you need to grasp how attackers exploit the protocol for location tracking. SS7 operates on a trust-based model, assuming all connected nodes are legitimate. This design flaw is the root of its vulnerabilities.

The Technical Breakdown

Accessing the SS7 Network: Attackers gain entry through leased connections, compromised telecom equipment, or insider access. A 2023 report noted that even small operators can purchase SS7 access for as little as a few thousand euros.
Sending Malicious Commands: Hackers use SS7 commands like SRI to query a target’s Home Location Register (HLR) for their International Mobile Subscriber Identity (IMSI) and current network. A follow-up PSI command retrieves the Cell-ID, revealing the device’s location.
Man-in-the-Middle (MitM) Attacks: By posing as a legitimate Mobile Switching Center (MSC), attackers intercept signaling messages, enabling real-time tracking or data theft.
Cross-Protocol Attacks: Even 4G/5G networks using the Diameter protocol are vulnerable when interoperating with SS7-based 2G/3G networks.

Real-World Example

In 2022, a surveillance firm in the Middle East used SS7 to track journalists traveling in the U.S., sending SRI and PSI commands from Saudi-based networks. This incident, reported by Citizen Lab, underscored how SS7 vulnerabilities enable cross-border espionage.

Understanding these mechanics is the first step to fortifying SS7 security and preventing unauthorized tracking.

Global Importance of SS7 Security

SS7 security isn’t just a technical issue—it’s a global imperative with implications for privacy, national security, and economic stability. As of 2025, 30% of mobile connections still rely on 2G/3G networks, ensuring SS7’s relevance despite 5G’s rise.

Key Impacts

Privacy Violations: SS7-based tracking exposes individuals to stalking, surveillance, and identity theft. High-profile targets like politicians and executives are particularly at risk.
National Security: State-sponsored actors exploit SS7 to monitor dissidents or gather intelligence. A 2024 DHS report highlighted China, Russia, and Iran as primary abusers of SS7 vulnerabilities in U.S. networks.
Economic Losses: SS7 attacks facilitate fraud, such as bypassing SMS-based 2FA for bank accounts, costing businesses millions annually.

Industry Response

Telecom associations like GSMA have pushed for firewalls and monitoring, but adoption remains uneven. Only 25% of global operators had deployed signaling firewalls by 2021, leaving many networks exposed. Robust SS7 security is essential to bridge this gap and protect the global telecom ecosystem.

Region-Specific Case Studies: SS7 Security in Action

SS7 vulnerabilities manifest differently across regions, shaped by infrastructure, regulations, and threat landscapes. Below are three case studies illustrating SS7 security challenges and solutions.

Case Study 1: Europe – Banking Fraud in Germany

In 2017, criminals exploited SS7 to intercept SMS-based transaction codes, draining bank accounts in Germany. The attackers accessed the SS7 network via a leased connection, highlighting the need for stricter access controls. German operators responded by deploying firewalls and phasing out SMS-based 2FA, reducing SS7-related fraud by 40% by 2020.

Case Study 2: Middle East – Surveillance in Saudi Arabia

A 2023 Citizen Lab report revealed Saudi networks using SS7 to track Saudi citizens in the U.S. By sending PSI commands, attackers obtained Cell-IDs, enabling precise location tracking. Almuqeet Systems, a telecom provider specializing in SMS firewalls, helped a regional operator implement real-time monitoring, blocking 85% of unauthorized SS7 queries.

Case Study 3: Africa – Fraud in Nigeria

Nigeria’s telecom market, reliant on 2G/3G, faced rampant SS7-based fraud in 2024. Attackers used SS7 to spoof SMS for phishing scams. Local operators adopted GSMA’s filtering guidelines, cutting fraudulent SMS traffic by 30%.

These cases show that while SS7 threats are universal, tailored SS7 security strategies can yield significant results.

Practical Approaches to Secure Your Network

Securing your network from SS7-based location tracking requires a multi-layered approach. Below are actionable strategies for telecom engineers and cybersecurity professionals.

1. Deploy Signaling Firewalls

Signaling firewalls filter SS7 traffic, blocking unauthorized commands like SRI and PSI. GSMA recommends firewalls at network boundaries to validate Global Titles (GTs) and detect anomalies. Almuqeet Systems offers advanced SMS firewalls that integrate with existing infrastructure, ensuring compliance with GSMA standards.

2. Implement Real-Time Monitoring

24/7 monitoring detects suspicious SS7 activity, such as unexpected roaming queries. Tools like LogRhythm SIEM integrate with Telecom Attack Discovery (TAD) to provide dashboards for anomaly detection.

3. Encrypt Communications

End-to-end encryption for SMS and calls reduces interception risks. Apps like Signal use encryption to bypass SS7 vulnerabilities, offering a user-level defense.

4. Restrict SS7 Access

Limit SS7 access to trusted operators and audit leased connections. Regular security assessments, as recommended by CSRIC, help identify rogue nodes.

5. Transition to Diameter

While 4G/5G networks use Diameter, which supports IPsec/TLS, interoperability with SS7 remains a risk. Accelerate 2G/3G phase-outs to minimize exposure.

Best SS7 Security Tools and Technologies

Choosing the right tools is critical for robust SS7 security. Here are top solutions for 2025:

LogRhythm SIEM: Integrates with TAD for real-time SS7 attack detection.
FirstPoint SIM-Based Protection: Offers user-level SS7 security for enterprises, ideal for IoT devices.
AdaptiveMobile Security: Provides advanced threat intelligence to block SS7 exploits.
SecurityGen: Specializes in signaling security for 2G/3G networks, with automated response features.

These tools, combined with best practices, form a comprehensive SS7 security framework.

Common Challenges and How to Overcome Them

Implementing SS7 security isn’t without hurdles. Here’s how to tackle common issues:

Challenge 1: Legacy Infrastructure

Issue: Many operators rely on outdated 2G/3G networks, increasing SS7 exposure. Solution: Create secure enclaves for legacy systems and prioritize 5G upgrades.

Challenge 2: Cost Constraints

Issue: Firewalls and monitoring systems require significant investment. Solution: Leverage open-source tools like OpenSS7 for cost-effective monitoring and partner with providers like SecurityGen for scalable solutions.

Challenge 3: Insider Threats

Issue: Insiders can sell SS7 access to attackers. Solution: Implement strict access controls and conduct regular audits.

Challenge 4: Global Interoperability

Issue: SS7’s global nature complicates uniform security standards. Solution: Adopt GSMA guidelines and collaborate with international operators for threat intelligence sharing.

FAQ: Quick Answers to SS7 Security Questions

Q: What is SS7 security?
A: SS7 security involves protecting the SS7 protocol from exploits like location tracking, SMS interception, and call eavesdropping through firewalls, monitoring, and encryption.

Q: How can I detect an SS7 attack?
A: Use SIEM tools like LogRhythm to monitor SS7 traffic for anomalies, such as unauthorized SRI or PSI commands.

Q: Is SS7 still relevant in 2025?
A: Yes, 30% of global mobile connections rely on 2G/3G networks, making SS7 security critical.

Q: Can end-users protect themselves from SS7 attacks?
A: Users can use encrypted apps like Signal and avoid SMS-based 2FA to minimize risks.

Conclusion: Building a Resilient Telecom Future

SS7 security is a cornerstone of modern telecom resilience. As vulnerabilities persist in 2025, driven by legacy networks and evolving threats, IT professionals and telecom engineers must act decisively. By deploying firewalls, monitoring traffic, and embracing encryption, you can shield your network from SS7-based location tracking. The case studies and tools outlined here provide a roadmap for success, but the journey requires ongoing vigilance and collaboration. Start today—your network’s security depends on it.

Master SS7 Security: Your Ultimate Guide to Protection