VoWiFi Attack Vectors
Comprehensive analysis of Voice over WiFi security vulnerabilities, attack methodologies, and exploitation techniques targeting ePDG and IMS infrastructure.
Critical VoWiFi Vulnerabilities
Evolved Packet Data Gateway authentication weaknesses allow attackers to bypass IKEv2/EAP-AKA authentication and establish unauthorized VoWiFi sessions.
Attack Techniques:
- EAP-AKA sequence number manipulation
- IKEv2 identity spoofing
- Certificate validation bypass
- Replay attack exploitation
Mitigation:
Implement strict EAP-AKA sequence validation, enforce mutual authentication, deploy certificate pinning, and monitor for authentication anomalies.
Vulnerabilities in IPsec tunnel establishment and maintenance enable man-in-the-middle attacks and traffic interception.
Attack Vectors:
- IKEv2 downgrade attacks
- IPsec SA parameter manipulation
- Tunnel hijacking via rekeying
- ESP packet injection
Impact:
Call interception, voice eavesdropping, SMS interception, location tracking, and service disruption.
SIP signaling vulnerabilities within the IPsec tunnel allow call manipulation and service abuse.
Exploitation Methods:
- SIP INVITE message manipulation
- Call-ID hijacking
- SDP parameter tampering
- Registration hijacking
Detection:
Monitor for abnormal SIP message patterns, unexpected call flows, registration anomalies, and SDP inconsistencies.
Attacks targeting the underlying WiFi network to compromise VoWiFi security before IPsec tunnel establishment.
Attack Types:
- Rogue WiFi access points
- Evil twin attacks
- DNS hijacking for ePDG discovery
- KRACK-style WiFi exploits
Prevention:
Use WPA3 encryption, implement ePDG FQDN validation, deploy certificate pinning, and educate users about rogue AP risks.
VoWiFi Attack Methodology
1Network Discovery
Identify VoWiFi infrastructure components including ePDG endpoints, IMS core elements, and WiFi network configurations.
Tools:
WiFi scanners, DNS enumeration tools, IKEv2 scanners, SIP discovery tools
2ePDG Analysis
Analyze ePDG configuration, supported authentication methods, IPsec parameters, and certificate validation mechanisms.
Focus Areas:
IKEv2 proposals, EAP-AKA implementation, certificate chains, cipher suites
3Vulnerability Assessment
Test for authentication bypass, IPsec weaknesses, SIP vulnerabilities, and WiFi network security issues.
Testing:
Authentication fuzzing, protocol downgrade attempts, certificate validation tests, SIP message manipulation
4Exploitation
Execute controlled attacks to validate vulnerabilities including tunnel hijacking, call interception, and service abuse.
Techniques:
MitM attacks, rogue ePDG deployment, SIP message injection, IPsec SA manipulation