bfla

bfla is a skill for Claude Code from PurpleAILAB/Decepticon. It costs 47 tokens per session (2,710 once invoked), scanned B, original, Apache-2.0.

A guide to broken function-level authorization, where a user with limited permissions can call an action reserved for administrators or staff. The problem can occur in APIs, GraphQL, gRPC, WebSockets, or background jobs even when the user interface hides the action.

In plain words
What is it for?
Use it to test administrative endpoints, API actions, real-time events, and job workflows with accounts that have different roles.
Why use it?
It helps find permission checks that are missing or enforced only in the interface rather than on the server.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter.

Good fit Use it to test administrative endpoints, API actions, real-time events, and job workflows with accounts that have different roles.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/purpleailab/decepticon/bfla
About the project

Decepticon is an autonomous red-team agent that coordinates AI agents, security tools, sandboxes, and supporting services for authorized cybersecurity assessments. Security researchers and red teams can run it through its Docker stack, cloud service, command-line interface, or Python SDK, with the catalogue entries representing its available skills.

PurpleAILAB/Decepticon · 5,491 stars · on GitHub · decepticon.red

Install

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.

Any agent
npx skills add PurpleAILAB/Decepticon --skill bfla
Clone the repo
git clone --depth 1 https://github.com/PurpleAILAB/Decepticon

Made for: Claude Code.

Wrote 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.

agentmods badge for bfla

README.md
[![agentmods](https://agentmods.dev/badge/skills/purpleailab/decepticon/bfla/github.svg)](https://agentmods.dev/skills/purpleailab/decepticon/bfla)
Your own site
<a href="https://agentmods.dev/skills/purpleailab/decepticon/bfla"><img src="https://agentmods.dev/badge/skills/purpleailab/decepticon/bfla/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for bfla

Your own site · 80×15
<a href="https://agentmods.dev/skills/purpleailab/decepticon/bfla"><img src="https://agentmods.dev/badge/skills/purpleailab/decepticon/bfla.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 47 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,710 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 3 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 9 findings, up to high

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • high Supply Chain · line 48
    Remote code is downloaded and executed. This bypasses code review and could introduce malicious code.
    Fix: Avoid downloading and executing remote scripts. Use trusted packages from PyPI/npm. If remote fetch is required, verify checksums and use HTTPS.
  • high Supply Chain · line 146
    Remote code is downloaded and executed. This bypasses code review and could introduce malicious code.
    Fix: Avoid downloading and executing remote scripts. Use trusted packages from PyPI/npm. If remote fetch is required, verify checksums and use HTTPS.
  • medium Data Exfiltration · line 65
    Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.
    Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
  • medium Data Exfiltration · line 96
    Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.
    Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
  • medium Data Exfiltration · line 113
    Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.
    Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
  • medium Data Exfiltration · line 146
    Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.
    Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
  • medium Data Exfiltration · line 173
    Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.
    Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
  • medium Data Exfiltration · line 197
    Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.
    Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
  • medium Data Exfiltration · line 202
    Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.
    Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00047 $0.02710
Opus 5 $0.00023 $0.01355
Sonnet 5 $0.00009 $0.00542
Haiku 4.5 $0.00005 $0.00271

Measured 9d ago against content hash f2fcba00450f, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade B, and why

bfla scanned grade B with 3 findings 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 9d 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.

Sends data to an external URLlowData exfiltration

A POST to an outside endpoint may be telemetry or may be exfiltration; either way the mod talks to somewhere, and you should know where.

curl -s -c basic.jar -X POST https://<TARGET>/login -d 'user=basic&pass=<pass>'

Downgraded: this mod is about security review, or the phrase is quoted, so it is likely naming the pattern rather than instructing it.

Downloads and executes remote codemediumSupply chain

curl | sh runs whatever the server returns today, which is not necessarily what it returned when this was reviewed.

curl -s https://<TARGET>/openapi.json 2>/dev/null | python3 -c "

Downgraded: this mod is about security review, or the phrase is quoted, so it is likely naming the pattern rather than instructing it.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

curl -s https://<TARGET>/static/main.js | grep -oE '"/api/[^"]*"' | sort -u
packages/decepticon/decepticon/skills/standard/exploit/web/bfla/SKILL.md · 252 lines

How it starts

The opening of the file, as written. The whole thing — 252 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Broken Function Level Authorization (BFLA)

BFLA is an action-level access control failure: a lower-privileged principal successfully invokes a function (HTTP endpoint, GraphQL mutation, gRPC method, WebSocket event, background job action) that should be restricted to a higher-privileged role. It is distinct from IDOR (T1190 object-level) — the surface here is the action itself, not the object ID. Enforcement must bind actor to action at every transport layer and every service boundary, not just at the UI or API gateway.

Authorized use only. Only test systems you are explicitly authorized to assess. Privilege escalation in production without authorization is a crime in most jurisdictions.

Attack Surface

  • REST/JSON admin endpoints hidden from the UI but still live on the server
  • GraphQL mutations and admin fields absent from the published schema but introspectable
  • gRPC methods listed via server reflection that bypass gateway checks
  • WebSocket events where only the handshake was authorized
  • Background job create/finalize/approve endpoints that re-use session but skip role checks
  • Internal microservice RPCs reachable via SSRF or exposed routing
  • Feature flags enforced client-side / at edge but not at the core service

High-Value Actions

  • Role/permission assignment, user impersonation, sudo/su endpoints
  • Refund, credit issuance, price override, order void/cancel
  • Export/bulk-download of all user data or PII
  • Account suspension, deletion, reactivation, verification override
  • Feature flag toggle, quota/grant adjustment, seat/license change
  • 2FA reset, email-change bypass, password-reset initiation for arbitrary accounts
  • Admin console CRUD (create user, delete user, assign group)

Reconnaissance

Build the Actor x Action Matrix

Before fuzzing, enumerate the roles and their expected actions:

# Capture all endpoints from JS bundles, API spec, and crawl
# Extract role-specific API paths from the frontend
curl -s https://<TARGET>/static/main.js | grep -oE '"/api/[^"]*"' | sort -u
curl -s https://<TARGET>/openapi.json 2>/dev/null | python3 -c "
import sys,json
spec = json.load(sys.stdin)
for path,methods in spec.get('paths',{}).items():
    for method,info in methods.items():
        tags = info.get('tags',[]) + info.get('x-roles',[]) + info.get('security',[])
        print(method.upper(), path, tags)
" 2>/dev/null

Read the full file on GitHub · 252 lines

Changes

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.

  1. 9d ago First seen · 252 lines · 47 tokens per session scan B f2fcba00450f

Subscribe to this mod's changes

bfla is a skill published in the GitHub repository PurpleAILAB/Decepticon (5,491 stars, last pushed 13d ago), licensed Apache-2.0. It adds 47 tokens to every session and 2,710 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it B with 3 findings (sends data to an external url, downloads and executes remote code, makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

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