Blending security with telecom.
Key Concepts:
- SS7 vulnerabilities
- LTE/5G security
- IMS security
- SIM authentication
- Network monitoring
- IDS/IPS for telecom
- Lawful interception
Why It Matters: Your cybersecurity background makes you unique—telecom + security is in-demand.
Labs/Practice: Simulated SS7 attacks; hardened telecom networks.
Tools Used: Wireshark, OpenSSL, Ansible.
Lesson 10: Telecom Security – Your BIG PLUS 🔐
The rare & high-demand combination: Deep telecom knowledge + Security expertise
This is one of the highest-value niches in telecommunications in 2026. Operators, vendors, governments, consultancies, and cybersecurity firms are actively searching for people who truly understand both signaling protocols and modern attack surfaces.
Why Telecom Security Stands Out on a Resume
- Critical infrastructure → regulated & high-stakes target
- Legacy protocols (SS7, Diameter) still in wide use → notoriously insecure
- 5G introduces new attack vectors while improving some old ones
- Very few engineers combine deep telecom domain knowledge with offensive/defensive security skills
- High-paying roles: Telecom Security Engineer, Threat Intelligence Analyst, Red Teamer for telcos, Security Architect
1. Legacy Attack Surface – SS7 & Diameter (Still Very Relevant)
SS7 remains heavily used for international roaming, SMS delivery, number portability, and supplementary services.
Major SS7 Attack Classes (most still possible in 2026 if no protection)
| Attack Type | Technique/Example | Impact | Mitigation (GSMA FS.07/FS.11) |
|---|---|---|---|
| Location Tracking | ProvideSubscriberInfo, AnyTimeInterrogation | Real-time cell-ID / GPS | Block ATI/PSI from foreign networks |
| SMS Interception | SendRoutingInfoForSM + forwardSMS | Bank OTPs, 2FA codes | Home Routing for SMS |
| Call Interception | InsertSubscriberData + UpdateLocation | Man-in-the-middle voice calls | Whitelist allowed MAP operations |
| Subscriber Impersonation | Fake InsertSubscriberData with IMSI | Identity hijacking, fraud | Strong authentication checks |
| Denial of Service | Flood with SRI-SM / ATI queries | HLR/HSS overload | Rate limiting + anomaly detection |
Access in 2026: grey interconnects, compromised partners, dark-web purchased access (prices have dropped but still exist).
Typical SS7 signaling network – SSP ↔ STP ↔ SCP
2. 4G / 5G Security – Improvements & New Risks
4G (LTE / EPC) – Better than 2G/3G but still vulnerable
- Mutual authentication (EPS-AKA)
- Remaining issues:
- IMSI catchers (rogue eNodeBs / Stingrays)
- Unauthenticated NAS signaling → DoS
- GTPv2-C spoofing
5G – Much Stronger Security Foundation
| Feature | Benefit | Still Possible Attack Vector |
|---|---|---|
| SUCI / SUPI encryption | Prevents plain IMSI over the air | Rogue gNB before authentication |
| 5G-AKA (stronger than EPS-AKA) | Better key derivation & protection against bidding-down attacks | Misconfigured home network |
| HTTP/2 + TLS 1.3 mandatory | SBI (Service Based Interface) encryption & integrity | API abuse if NEF poorly secured |
| SEPP (Security Edge Protection Proxy) | Encrypted & integrity-protected interconnect traffic | Insider threats at interconnect |
| Network Slicing security | Slice isolation, dedicated authentication & authorization | Cross-slice leakage if misconfigured |
5G Service-Based Architecture with mandatory security elements
3. Defensive Techniques You Should Know
- SS7 / Diameter firewalls (GSMA FS.07, FS.11, FS.19)
- Home Routing for SMS in roaming
- TLS 1.3 everywhere + strong cipher suites
- Signaling anomaly detection (ML-based)
- Zero-trust in 5GC: least privilege per NF
- Continuous monitoring & SIEM for signaling spikes
- Lawful Interception must be secured (encrypted delivery + audit logs)