Telco Security

SIGTRAN Attack Vectors

Comprehensive guide to SIGTRAN protocol vulnerabilities, SCTP exploitation, M3UA attacks, and security testing methodologies for SS7-over-IP infrastructure.

Critical SIGTRAN Attack Vectors

SCTP Association Flooding
High

Overwhelming SIGTRAN endpoints with SCTP association requests to cause denial of service and resource exhaustion.

Techniques:

  • Basic SCTP INIT flooding
  • Cookie manipulation attacks
  • Multi-homing exploitation
  • Association state exhaustion

Countermeasures:

Implement SCTP rate limiting, deploy IP-based ACLs, configure resource limits, and use SCTP-aware IPS systems.

M3UA Message Spoofing
Critical

Injecting fake M3UA messages to manipulate signaling routing, execute SS7 attacks, or disrupt telecommunications services.

Attack Methods:

  • Routing key manipulation
  • ASP state manipulation
  • DATA message injection
  • Management message spoofing

Impact:

Traffic redirection, SS7 attack propagation, service disruption, and unauthorized access to signaling networks.

SCTP Authentication Bypass
Critical

Circumventing SCTP authentication mechanisms to establish unauthorized associations and inject malicious traffic.

Exploitation:

  • AUTH chunk manipulation
  • Shared key exploitation
  • HMAC parameter tampering
  • Weak key management abuse

Prevention:

Implement strong key management, use unique keys per endpoint pair, rotate keys regularly, and monitor authentication failures.

Signaling Gateway Attacks
High

Targeting the boundary between SS7 and IP networks to compromise signaling integrity and propagate attacks across domains.

Attack Types:

  • Protocol translation exploitation
  • Gateway overload attacks
  • Cross-domain attack propagation
  • Boundary filtering bypass

Mitigation:

Deploy robust input validation, implement traffic rate limiting, use deep packet inspection, and maintain separate security domains.

SIGTRAN Security Testing Methodology

1Network Discovery

Identify SIGTRAN components including SCTP endpoints, adaptation layers (M2PA, M3UA, SUA), Application Servers, and Signaling Gateways.

Tools:

SCTP Scanner, Wireshark with SIGTRAN dissectors, nmap with SCTP scripts, custom mapping tools

2Configuration Analysis

Evaluate SCTP association parameters, authentication implementation, access controls, and adaptation layer security configurations.

Deliverables:

SCTP security configuration report, adaptation layer assessment, security gap analysis

3Vulnerability Assessment

Test for unauthenticated associations, message filtering weaknesses, spoofing vulnerabilities, DoS susceptibility, and boundary protection gaps.

Tools:

SIGTRAN vulnerability scanner, SCTP fuzzing tools, M3UA message crafting tools

4Exploitation & Reporting

Execute controlled attacks including association hijacking, M3UA spoofing, SS7 message injection, and document findings with remediation recommendations.

Outputs:

Comprehensive security assessment report, technical findings, remediation roadmap

Related Attack Vectors