IMS Attacks & Security Analysis
Advanced IP Multimedia Subsystem attack methodologies, VoLTE security vulnerabilities, and comprehensive penetration testing techniques for telecommunications infrastructure.

IMS Architecture & Components
- P-CSCF (Proxy Call Session Control Function)
- S-CSCF (Serving Call Session Control Function)
- I-CSCF (Interrogating Call Session Control Function)
- HSS (Home Subscriber Server)
- SIP (Session Initiation Protocol)
- Diameter (Authentication & Authorization)
- RTP/SRTP (Media Transport)
- HTTP/2 (Service Layer)

Detailed VoLTE Attack Scenarios
This attack exploits weaknesses in SIP authentication mechanisms by intercepting REGISTER requests and responses. The attacker positions themselves between the UE and P-CSCF to capture authentication challenges and either replay them or manipulate the registration process to redirect calls to attacker-controlled endpoints.
Prerequisites
- Network access to SIP signaling path
- Ability to intercept SIP traffic
- Knowledge of target subscriber identities
- Understanding of IMS authentication flows
Attack Execution Steps
Position attacker infrastructure in the signaling path between UE and P-CSCF
Deploy rogue base station or compromise network infrastructure to intercept SIP traffic
Monitor and capture SIP REGISTER messages
Use packet capture tools to monitor SIP traffic on UDP port 5060 or TLS port 5061
Analyze captured authentication challenges and responses
Extract WWW-Authenticate headers and analyze digest authentication parameters
Craft malicious REGISTER messages to hijack registration
Create spoofed REGISTER requests with modified Contact headers pointing to attacker infrastructure
Redirect incoming calls to attacker-controlled endpoints
Respond to INVITE messages and establish media sessions with attacker infrastructure
Comprehensive Mitigation Framework
Network Security
- SIP Firewall deployed
- Network segmentation
- Access controls
Encryption
- TLS for signaling
- SRTP for media
- Key management
Monitoring
- Real-time monitoring
- Anomaly detection
- Incident response
VoLTE Security Mitigation Strategies
Security Impact
Attack Categories & Vectors
Security Testing Tools
CVE Database
Buffer overflow vulnerability in IMS core SIP stack allowing remote code execution
Affected Components
Impact
Authentication bypass in VoLTE call setup allowing unauthorized call establishment
Affected Components
Impact
Standards & Compliance Framework
Official GSMA security guidelines for mobile networks, including IMS security recommendations and VoLTE security best practices.
- • FS.31 - IMS Security Guidelines
- • FS.19 - VoLTE Security Guide
- • FS.40 - Network Equipment Security
Technical specifications for mobile telecommunications, including IMS architecture and security requirements.
- • TS 23.228 - IMS Architecture
- • TS 33.203 - IMS Security
- • TS 24.229 - IMS Call Control
European standards for telecommunications security, including IMS and VoLTE security specifications.
- • TS 187 001 - IMS Security
- • TS 133 203 - IMS Security
- • ES 203 119 - VoLTE Security
US federal cybersecurity standards and guidelines applicable to telecommunications infrastructure.
- • SP 800-53 - Security Controls
- • SP 800-171 - CUI Protection
- • Cybersecurity Framework
EU cybersecurity guidelines and threat landscape reports for telecommunications sector.
- • 5G Security Guidelines
- • Telecom Threat Landscape
- • ICS/SCADA Security
International standards for telecommunications security and network protection.
- • X.805 - Network Security
- • X.1051 - VoIP Security
- • Y.2701 - NGN Security
Security Domain | 3GPP | GSMA | ETSI | NIST | ENISA |
---|---|---|---|---|---|
Authentication & Authorization | TS 33.203 | FS.31 | TS 187 001 | SP 800-63 | 5G Guidelines |
Encryption & Key Management | TS 33.210 | FS.19 | TS 133 203 | SP 800-57 | Crypto Guidelines |
Network Security | TS 33.401 | FS.40 | TS 103 523 | SP 800-53 | Network Security |
VoLTE Security | TS 24.229 | FS.19 | ES 203 119 | SP 800-58 | VoIP Security |
Incident Response | TS 32.111 | FS.11 | TS 132 111 | SP 800-61 | Incident Handling |
Privacy Protection | TS 33.501 | FS.26 | TS 133 501 | Privacy Framework | GDPR Guidelines |
Regulatory Compliance Notice
IMS Security Compliance Checker
Compliance Gap Identified
Authentication and Key Agreement (AKA) must be implemented for IMS access
Configure HSS with proper AKA vectors and implement AKA procedures in P-CSCF
All media streams must be encrypted using SRTP
Configure media gateways to negotiate SRTP and implement proper key management
IMS components must be properly segmented from other network elements
Deploy firewalls and VLANs to isolate IMS core functions
SIP signaling must be protected using TLS encryption
Configure all SIP entities to use TLS and implement proper certificate management
Real-time security monitoring must be implemented
Deploy SIEM solutions and configure security event correlation
Formal incident response procedures must be established
Develop incident response playbooks and train response teams
User privacy must be protected according to applicable regulations
Implement data minimization and user consent mechanisms
All security-relevant events must be logged
Configure centralized logging and implement log retention policies
Frequently Asked Questions
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