telecom-surface-triage

Identify and safely triage internet-exposed telecom core elements like GBA/BSF, SIP/IMS, and Diameter interfaces.

7|4|Updated Jun 22, 2026
One-click install
npx skills add https://github.com/dbx0/skills --skill telecom-surface-triage-dbx0
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: telecom-surface-triage
Source: https://github.com/dbx0/skills/tree/main/skills/infra-network/initial-access/telecom-surface-triage
Command: npx skills add https://github.com/dbx0/skills --skill telecom-surface-triage-dbx0

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve? Generic web scanners misclassify exposed mobile-carrier core network elements as ordinary web servers, causing security researchers to miss critical cellular-auth exposures or, worse, to probe them unsafely and touch subscriber data. ## Core Features & Use Cases - Element Recognition: Detect telecom core infrastructure from hostname tokens (bsf, ims, rcs, hss, diameter, epc) and response signals like 3GPP SOAP namespaces, SIP banners, and GSMA-issued certificates. - Trust Boundary Mapping: Match each element (BSF, HSS/AAA, P-CSCF, XCAP/XDM, SCEF/NEF) to the interface and authentication it should enforce, so misconfigurations become obvious. - Safe Exposure Proof: Demonstrate unauthenticated access using fake identifiers, mTLS checks via openssl, and sibling-node contrast without ever touching real subscriber data. - Use Case: During a carrier bug bounty, recon surfaces nds.bsf.example.com returning a SOAP fault with a urn:3gpp:gba namespace. Use this Skill to confirm it is an unauthenticated GBA BSF, prove it processes operations, and write it up as a cellular-auth critical finding. ## Quick Start Ask the agent to triage a suspicious host like nds.bsf.example.com found during recon and determine whether it is an exposed telecom core element, using only safe non-subscriber probes.

Frequently Asked Questions about telecom-surface-triage

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I identify exposed telecom core infrastructure during recon?

Search subdomains for tokens like bsf, ims, rcs, xcap, hss, diameter, and epc, then check responses for 3GPP SOAP namespaces, SIP banners, or certificates issued to GSM Association. These signals distinguish carrier core elements from ordinary web servers.

How to test if a GBA BSF server requires mutual TLS?

Run openssl s_client -connect host:443 -servername host and look for the message 'No client certificate CA names sent', which means the server does not request a client certificate. That proves mutual TLS is not enforced on the interface.

What is a 3GPP GBA BSF and why is its exposure critical?

A BSF is the Bootstrapping Server Function in 3GPP Generic Bootstrapping Architecture that derives subscriber key material with the HSS. An internet-reachable, unauthenticated BSF violates TS 33.220/33.210 and typically qualifies as a critical cellular-auth finding in carrier bug bounty programs.

Can I test telecom core elements without accessing subscriber data?

Yes, use deliberately fake identifiers such as a non-subscriber B-TID or nafId=test.invalid and observe whether the error response changes, proving the element processes operations. Never submit real IMSI, MSISDN, or IMPI values, and stop immediately if subscriber data appears.

Why does my telecom finding get dismissed as intended public exposure?

Programs often claim an endpoint is public by design, so contrast it with sibling nodes in the same cluster using identical requests. When peers return 401, 403, or 412 while your target returns 200, you have credible evidence of a misconfiguration rather than intended behavior.