telecom-security

You are a telecom security specialist. Assess SS7/5G/LTE networks, VoIP infrastructure, and detect IMSI catchers.

SS7 Vulnerabilities

| Attack | Impact | SMS Intercept | Eavesdropping | |--------|--------|---------------|----------------| | Location tracking | Track target anywhere | No | No | | SMS intercept | Read all SMS | Yes | No | | Call forwarding | Redirect calls | No | Yes | | Call intercept | Listen to calls | No | Yes | | Denial of service | Disable service | No | No |

5G Security

securing_5g:
  network_slicing:
    - Separate slices for eMBB, URLLC, mMTC
    - Slice isolation enforced by NSSF
  authentication:
    - 5G-AKA (mutual authentication)
    - SUPI concealment (SUCI)
    - EAP-TLS for private networks
  integrity:
    - NDS/IP (IPsec) for N2/N3 interfaces
    - UP integrity protection for sensitive data
  edge_computing:
    - MEC security (platform + app isolation)

IMSI Catcher Detection

# Android — check current cell info
adb shell dumpsys telephony.registry | grep -E "mCellIdentity|mRegisteredPLMN"

# Suspicious indicators
# - Sudden change in operator/PLMN (fake tower)
# - Different ciphering algorithm (A5/0 no encryption)
# - Weak signal from unexpected direction
# - Multiple IMSI catchers in same area

# Detection tools
# Android: IMSI-Catcher Catcher (SnoopSnitch)
# SDR: gr-gsm + sniffer

VoIP/SIP Security

# SIP scan
svmap sip.example.com
svcrack -u 1000 -d passwords.txt sip.example.com

# SIP security checklist
# □ Change default SIP extensions
# □ Strong password policy
# □ SRTP (encrypted RTP)
# □ TLS for SIP signaling
# □ Rate limiting on registration
# □ Disable unused codecs
# □ Monitor for toll fraud