Methodology Overview
VoLTE security testing requires a systematic approach that addresses the complexity of the IMS architecture and the various protocols involved in voice service delivery.
Key Focus Areas
- IMS Core Security: CSCF, HSS, and application server assessment
- Signaling Protocols: SIP and Diameter security analysis
- Media Plane: RTP/SRTP stream security testing
- Authentication: IMS-AKA and security association testing
Testing Phases
1. Reconnaissance
Information gathering and network discovery
2-3 days
Key Activities
- IMS network topology mapping
- Service discovery and enumeration
- Protocol identification (SIP, Diameter, RTP)
- Network element identification (P-CSCF, S-CSCF, HSS)
- Security policy analysis
Recommended Tools
Nmap
Wireshark
SIPVicious
Custom scanners
2. IMS Core Assessment
Deep analysis of IMS core components
3-5 days
Key Activities
- CSCF security assessment
- HSS vulnerability analysis
- Application server testing
- Media gateway evaluation
- Policy server assessment
Recommended Tools
SIP testing tools
Diameter clients
Protocol analyzers
3. Signaling Analysis
SIP and Diameter protocol security testing
4-6 days
Key Activities
- SIP message manipulation
- Authentication bypass testing
- Session hijacking attempts
- Diameter interface exploitation
- Protocol fuzzing
Recommended Tools
SIPp
SIPVicious
Custom Diameter tools
Fuzzing frameworks
4. Media Plane Testing
RTP/SRTP media stream security assessment
2-4 days
Key Activities
- RTP stream interception
- SRTP key extraction
- Media injection attacks
- Codec manipulation
- Quality degradation testing
Recommended Tools
RTPBreak
RTPInject
Scapy
Custom media tools
5. Authentication Testing
IMS authentication and authorization testing
3-4 days
Key Activities
- AKA authentication bypass
- Credential extraction
- Identity spoofing
- Authorization escalation
- Token manipulation
Recommended Tools
Authentication tools
Crypto analyzers
Custom exploits
6. Exploitation
Active exploitation of identified vulnerabilities
2-5 days
Key Activities
- Service disruption attacks
- Call interception
- Data exfiltration
- Privilege escalation
- Persistent access establishment
Recommended Tools
Custom exploits
Metasploit modules
Attack frameworks
Testing Best Practices
Safety Guidelines
- •Always obtain proper authorization before testing
- •Use isolated test environments when possible
- •Monitor for service disruption during testing
- •Document all testing activities and findings
- •Follow responsible disclosure practices
Common Pitfalls
- •Overlooking encrypted signaling channels
- •Insufficient media plane security testing
- •Ignoring emergency call procedures
- •Missing roaming interface security
- •Inadequate authentication testing