Telco Security

SS7 Attacks & Security Vulnerabilities

Comprehensive database of SS7 protocol vulnerabilities, attack vectors, real-world scenarios, and security testing methodologies

What is SS7?

Signaling System No. 7 (SS7) is a critical telecommunications protocol suite used for setting up and tearing down telephone calls, routing SMS messages, and supporting other essential services in mobile networks. Despite its importance, SS7 was designed with minimal security controls, making it vulnerable to various attacks that can compromise subscriber privacy, location tracking, and service integrity.

Security Challenges
  • • Lack of authentication mechanisms in the original protocol design
  • • No encryption for signaling messages
  • • Trust-based network architecture that assumes all connected operators are legitimate
  • • Limited access controls between interconnected networks
  • • Difficulty implementing security patches across global infrastructure
  • • Legacy equipment with outdated security features
  • • Insufficient monitoring and logging capabilities
  • • Complex international roaming agreements creating security gaps

Attack Categories

Location Intelligence
Advanced location tracking and surveillance techniques

SendRoutingInfoForSM Attack

Critical

Enhanced location tracking using SMS routing information with geolocation correlation. Used by NSO Group's Pegasus spyware for initial target location.

CVE-2014-0016 | Discovered by Tobias Engel (Srlabs)

AnyTimeInterrogation Attack

Critical

Advanced location tracking using AnyTimeInterrogation with minimal detection footprint. Used by intelligence agencies for surveillance operations.

CVE-2014-0017 | Discovered by P1 Security

Advanced Interception
Sophisticated call and SMS interception techniques

UpdateLocation Manipulation

Critical

Sophisticated call interception using UpdateLocation with traffic analysis and call forwarding. Used in corporate espionage and government surveillance operations.

CVE-2014-0018 | Discovered by Karsten Nohl (SRLabs)

InsertSubscriberData Attack

Critical

Modify subscriber data to intercept SMS messages and redirect calls through attacker-controlled infrastructure.

Real-World Incidents

German Politicians Surveillance (2016)
60 Minutes CBS investigation

60 Minutes CBS investigation revealed SS7 vulnerabilities being exploited to track German politicians, demonstrating real-world SS7 exploitation and high-profile privacy breaches.

SendRoutingInfoForSMLocation tracking
NSO Group Pegasus SS7 Integration (2017-2021)
Citizen Lab research

Pegasus spyware used SS7 vulnerabilities for initial target location before deploying mobile malware, enabling sophisticated surveillance operations against journalists and activists.

Location trackingCall interceptionSMS interception
Ukrainian Telecom Attack (2014)
Security research reports

SS7 attacks used during Ukrainian conflict to intercept communications and track military personnel, resulting in military intelligence compromise and operational security breach.

Call interceptionLocation trackingService disruption

Mitigation Strategies

SS7 Firewall Implementation

Deploying specialized firewalls to filter malicious SS7 traffic. SS7 firewalls can be configured to block unauthorized MAP operations, filter messages based on source Global Title, and implement category-based filtering for high-risk operations.

SMS Home Routing

Architecture that prevents direct access to the HLR for SMS-related operations. SMS Home Routing creates a separation between the SMS service center and the HLR, preventing attackers from using SendRoutingInfoForSM to locate subscribers.

Real-time Monitoring and Analytics

Continuous monitoring of SS7 traffic for anomalies. Deploying monitoring systems that can detect unusual patterns in SS7 signaling traffic and alert operators to potential attacks in progress.

Enhanced Authentication Mechanisms

Implementing stronger authentication for SS7 operations. Deploy mutual authentication between network elements, implement digital signatures for critical operations, and use time-based tokens to prevent replay attacks.