Telecommunications Security Testing Methodology
Professional approach to testing telecommunications infrastructure security
Legal Notice: All security testing must be conducted with explicit written authorization from the network operator. Unauthorized testing of telecommunications networks is illegal and may result in criminal prosecution.
Comprehensive
Covers all major telecommunications protocols and attack vectors
Structured
Step-by-step approach ensuring thorough coverage and documentation
Professional
Industry-standard methodology used by security professionals
Phase 1: Planning and Scoping
Objectives
Define clear objectives and boundaries for the security assessment
Key Activities:
- • Obtain written authorization from network operator
- • Define scope: protocols, systems, and testing boundaries
- • Identify testing constraints and restrictions
- • Establish communication channels with stakeholders
- • Create testing schedule and timeline
- • Set up secure testing environment
Required Documentation:
- ✓ Signed authorization letter
- ✓ Scope of work document
- ✓ Rules of engagement
- ✓ Emergency contact information
- ✓ Non-disclosure agreement
Phase 2: Reconnaissance
Network Information Gathering
- • Identify Mobile Country Code (MCC) and Mobile Network Code (MNC)
- • Determine signaling protocols in use (SS7, SIGTRAN, Diameter)
- • Map network topology and interconnections
- • Identify Global Title (GT) ranges
- • Discover Point Codes and SCCP addresses
- • Enumerate SIP/IMS infrastructure
Tools and Techniques
- SS7SigPloit, SS7MAP
- GTPWireshark, gtp-scan
- SIPSIPVicious, sippts
- OSINTPublic databases, operator info
Phase 3: Vulnerability Assessment
Protocol-Specific Testing
Systematic assessment of each protocol for known vulnerabilities
SS7SS7 Vulnerability Assessment
- • Test for location tracking vulnerabilities (SendRoutingInfo)
- • Check SMS interception capabilities (ForwardSM)
- • Assess call interception risks (UpdateLocation)
- • Test authentication bypass (InsertSubscriberData)
- • Verify SCCP filtering effectiveness
GTPGTP Vulnerability Assessment
- • Test for user impersonation (Create Session)
- • Check DoS vulnerabilities (Echo Request flooding)
- • Assess data interception risks (GTP-U tunneling)
- • Test IMSI disclosure vulnerabilities
- • Verify GTP firewall rules
SIPSIP/VoIP Vulnerability Assessment
- • Test registration hijacking
- • Check authentication bypass methods
- • Assess call manipulation vulnerabilities
- • Test for DoS attack vectors
- • Verify TLS/SRTP implementation
Phase 4: Controlled Exploitation
Exploitation must be conducted in a controlled manner with continuous monitoring and immediate rollback capability. Never perform actions that could disrupt live services.
Safe Exploitation Guidelines
Pre-Exploitation Checklist:
- ✓ Verify authorization for exploitation phase
- ✓ Ensure monitoring systems are active
- ✓ Prepare rollback procedures
- ✓ Notify stakeholders of testing window
- ✓ Use isolated test environment when possible
Exploitation Approach:
- • Start with least invasive tests
- • Document every action and result
- • Monitor for unintended side effects
- • Limit scope to authorized targets only
- • Stop immediately if issues arise
Phase 5: Documentation and Reporting
Comprehensive Reporting
Deliver actionable findings with clear remediation guidance
Report Structure:
- Executive Summary - High-level overview for management
- Methodology - Testing approach and scope
- Findings - Detailed vulnerability descriptions with evidence
- Risk Assessment - CVSS scores and business impact analysis
- Recommendations - Prioritized remediation steps
- Appendices - Technical details, tool outputs, references
For Each Finding Include:
- • Vulnerability description and affected systems
- • Proof of concept with screenshots/logs
- • Risk rating (Critical/High/Medium/Low)
- • Business impact assessment
- • Detailed remediation steps
- • References to standards (3GPP, GSMA, etc.)
Best Practices
Do's
- ✓ Always obtain written authorization
- ✓ Document everything thoroughly
- ✓ Use isolated test environments
- ✓ Follow responsible disclosure
- ✓ Maintain confidentiality
- ✓ Stay within defined scope
Don'ts
- ✗ Never test without authorization
- ✗ Don't disrupt live services
- ✗ Avoid testing on production systems
- ✗ Don't exceed authorized scope
- ✗ Never share findings publicly
- ✗ Don't use findings maliciously