Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add ShulkwiSEC/bb-huge --skill authz-bypassgit clone --depth 1 https://github.com/ShulkwiSEC/bb-hugeWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/shulkwisec/bb-huge/authz-bypass)<a href="https://agentmods.dev/skills/shulkwisec/bb-huge/authz-bypass"><img src="https://agentmods.dev/badge/skills/shulkwisec/bb-huge/authz-bypass.svg" alt="Measured on agentmods" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00110 | $0.02251 |
| Opus 5 | $0.00055 | $0.01125 |
| Sonnet 5 | $0.00022 | $0.00450 |
| Haiku 4.5 | $0.00011 | $0.00225 |
Grade A, and why
authz-bypass scanned grade A with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 7d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
curl -s "https://TARGET/invoice?id=12345" \ How it starts
The opening of the file, as written. The whole thing — 181 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Authorization Bypass and IDOR
What Is Broken and Why
Access control failures occur when applications enforce authorization only at the UI layer, rely
on obscurity of object identifiers, or fail to validate that the requesting session owns the
referenced resource. Horizontal bypass allows users to access peer accounts' data by swapping
identifiers. Vertical bypass allows low-privileged users to invoke admin-only operations by
replaying high-privilege request structures with a low-privilege session. IDOR (Insecure Direct
Object Reference) exposes any predictable or discoverable resource identifier as a direct handle
to unauthorized data. Special request headers (X-Original-URL, X-Rewrite-URL) can override
routing in some reverse proxy configurations, bypassing ACL rules applied at the path level.
Key Signals
- Numeric or sequential IDs in URLs or parameters:
invoice=12345,user=100,EventID=1000001 - Different accounts created at similar times with adjacent IDs
- Responses containing another user's PII, financial data, or account settings when ID swapped
- Admin-only actions (delete, promote, deactivate) accessible via session swap
X-Original-URLorX-Rewrite-URLheaders triggering 404 vs 403 — confirms header processingX-Forwarded-For: 127.0.0.1bypassing IP-based access restrictions to admin panels- GUIDs or opaque tokens that, when substituted, return another user's object
menuitem=oraccessPage=parameters accepting values outside a user's visible menu set- Password change endpoint accepting
user=parameter without session-ownership validation
Methodology
- Map object references: During application use, record every parameter that references a resource (document ID, user ID, order number, file name, menu item).
- Create test accounts: Register at least two accounts at different privilege levels; note all object IDs each account owns.
- Horizontal bypass: With Account B's session, request objects owned by Account A by substituting Account A's IDs.
- Vertical bypass: With low-privilege session, replay admin-only requests (delete, role change, config update) captured from an admin session.
- IDOR enumeration: Increment/decrement integer IDs; test adjacent values; attempt GUID prediction if UUIDs appear time-seeded.
- Header injection test: Send
X-Original-URL: /adminandX-Rewrite-URL: /adminon a request to/; 404 response (vs 403 on direct access) confirms header support. - IP spoofing header test: Send
X-Forwarded-For: 127.0.0.1on requests to IP-restricted admin endpoints; observe access control difference. - POST-to-GET conversion: Test if server accepts session ID or IDOR parameter via GET when originally designed for POST.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 7d ago First seen · 181 lines · 110 tokens per session scan A 74a278902e1b
authz-bypass is a skill published in the GitHub repository ShulkwiSEC/bb-huge (22 stars, last pushed 1mo ago), licensed MIT. It adds 110 tokens to every session and 2,251 once invoked, about $0.0006 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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