3GPP TS 33.519 V18 — 5G SCAS for NEF

Q: What does the Scope section cover in 3GPP TS 33.519 V18 — 5G SCAS for NEF?

The Scope section provides detailed technical specifications, security considerations, and implementation guidance as documented in 3GPP TS 33.519 V18 — 5G SCAS for NEF. This content is part of the BLACKLABS 3GPP Security Library.

Q: What does the NEF Network Product Class Definition section cover in 3GPP TS 33.519 V18 — 5G SCAS for NEF?

The NEF Network Product Class Definition section provides detailed technical specifications, security considerations, and implementation guidance as documented in 3GPP TS 33.519 V18 — 5G SCAS for NEF. This content is part of the BLACKLABS 3GPP Security Library.

Q: What does the NEF-Specific Threats section cover in 3GPP TS 33.519 V18 — 5G SCAS for NEF?

The NEF-Specific Threats section provides detailed technical specifications, security considerations, and implementation guidance as documented in 3GPP TS 33.519 V18 — 5G SCAS for NEF. This content is part of the BLACKLABS 3GPP Security Library.

Q: What does the Security Requirements and Test Cases section cover in 3GPP TS 33.519 V18 — 5G SCAS for NEF?

The Security Requirements and Test Cases section provides detailed technical specifications, security considerations, and implementation guidance as documented in 3GPP TS 33.519 V18 — 5G SCAS for NEF. This content is part of the BLACKLABS 3GPP Security Library.

Q: What does the SCAS Test Case Summary section cover in 3GPP TS 33.519 V18 — 5G SCAS for NEF?

The SCAS Test Case Summary section provides detailed technical specifications, security considerations, and implementation guidance as documented in 3GPP TS 33.519 V18 — 5G SCAS for NEF. This content is part of the BLACKLABS 3GPP Security Library.

BLACKLABS

3GPP TS 33.519

5G Security Assurance Specification (SCAS) for the Network Exposure Function (NEF) network product class

V18.3.0 (2024-06) — Release 18 SCAS Product Class

1. Scope

▶

Defines security requirements and test cases for the NEF network product class. The NEF exposes 5GC capabilities to external Application Functions (AFs) via northbound APIs, acting as the security gateway between the 5GC and external applications.

4. NEF Network Product Class Definition

▶

External 5G Core ┌──────────┐ ┌──────────────────────┐ │ AF │──Nnef (HTTPS)────►│ NEF (this) │ │ (3rd │ │ │ │ party) │ │ API translation │ └──────────┘ │ Rate limiting │ │ AuthZ enforcement │ │ │ └───┬────┬────┬────────┘ │ │ │ Nudm │ │ │ Npcf ┌────────┘ │ └────────┐ ▼ ▼ ▼ ┌────────┐ ┌────────┐ ┌────────┐ │ UDM │ │ SMF │ │ PCF │ └────────┘ └────────┘ └────────┘

5. NEF-Specific Threats

▶

TR 33.926 §5.3.5 Unauthorized external access to 5GC via NEF ▶

TR 33.926 §6.3.2 NF application threats via exposed APIs ▶

TR 33.926 §6.3.2.1 JSON parser exploits on API input ▶

API abuse: External AF exceeding authorized scope to access subscriber data
SUPI exposure: NEF translating internal SUPI to external without privacy controls
Rate limit bypass: DDoS via excessive API calls from compromised AF

6. Security Requirements and Test Cases

▶

TC_NEF_API_AUTH

CRITICAL

Procedure

Verify external AF requires TLS client certificate or API key + OAuth 2.0
Verify scope enforcement (AF can only access subscribed APIs)
Send request for non-subscribed API → verify 403 Forbidden
Verify rate limiting is enforced per AF

TC_NEF_SUPI_PRIVACY

CRITICAL

Procedure

Verify NEF translates SUPI to GPSI before exposing to external AF
Verify internal 5GC identifiers (NF instance IDs, internal IPs) are never exposed to AFs
Verify subscription correlation attacks are mitigated

TC_NEF_INPUT_VALIDATION

CRITICAL

Procedure

Send malformed JSON payloads → verify proper error handling (no crash, no info leak)
Send oversized payloads → verify request size limits enforced
Send injection payloads in API parameters → verify sanitized

TR 33.926 §6.3.2.1 JSON parser exploits ▶

7. SCAS Test Case Summary

▶

Test Case ID	Category	Priority
TC_NEF_API_AUTH	API Security	CRITICAL
TC_NEF_SUPI_PRIVACY	Privacy	CRITICAL
TC_NEF_INPUT_VALIDATION	Input Validation	CRITICAL
Plus ALL test cases from TS 33.117

3GPP TS 33.519

1. Scope

4. NEF Network Product Class Definition

5. NEF-Specific Threats

6. Security Requirements and Test Cases

7. SCAS Test Case Summary

3GPP TS 33.519 V18 — 5G SCAS for NEF Summary

Key Sections