business-logic-vulnerabilities

business-logic-vulnerabilities is a skill for Claude Code, Codex from miru-zero/zero-brain. It costs 37 tokens per session (7,606 once invoked), scanned A, a copy of business-logic-vulnerabilities, MIT.

A playbook for finding business-logic security flaws: bugs in how an application's workflows, rules, or permissions operate. It covers issues such as race conditions, price manipulation, coupon abuse, and authorization gaps.

In plain words
What is it for?
Use it to review workflows, model state changes, and investigate payment, login, registration, privacy, and authorization logic.
Why use it?
These problems often depend on how multiple steps interact and may not be found by ordinary security scanners.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: positional $N argument.

Not installable on its own: it reads a path above its own folder, which only exists inside its repository. The line is Bypass: http://target/FilterDemo/../../index.jsp → 200 (filter sees "../../", URL parser collapses).

Install

Getting it into your agent

There is no command for this one: it runs only inside a plugin, and the catalogue could not identify which plugin ships it. The source is linked below.

Made for: Claude Code, Codex.

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 business-logic-vulnerabilities

README.md
[![agentmods](https://agentmods.dev/badge/skills/miru-zero/zero-brain/business-logic-vulnerabilities.svg)](https://agentmods.dev/skills/miru-zero/zero-brain/business-logic-vulnerabilities)
Your own site
<a href="https://agentmods.dev/skills/miru-zero/zero-brain/business-logic-vulnerabilities"><img src="https://agentmods.dev/badge/skills/miru-zero/zero-brain/business-logic-vulnerabilities.svg" alt="Measured on agentmods" height="20"></a>
Per session 37 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 7,606 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. Scan, not verified.
Origin 98% copy Near-identical to another mod 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 $0.00037 $0.07606
Opus 5 $0.00018 $0.03803
Sonnet 5 $0.00007 $0.01521
Haiku 4.5 $0.00004 $0.00761

Measured 5d ago against content hash 3e2c2bfc060b, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

business-logic-vulnerabilities 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 5d 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.

For each hit, replay the URL anonymously (curl, VLC, flv.js demo at `https://bilibili.github.io/flv.js/demo/`). If the URL plays without a session, you've broken VIP gating. Defense: use signed, short-TTL URLs bound to u
Origin

This is a copy

98% identical to business-logic-vulnerabilities — 4 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

skills/business-logic-vulnerabilities/SKILL.md · 712 lines

How it starts

The opening of the file, as written. The whole thing — 712 lines — stays where its author put it; the contents beside it link to each section on GitHub.

SKILL: Business Logic Vulnerabilities — Expert Attack Playbook

AI LOAD INSTRUCTION: Business logic flaws are scanner-invisible and high-reward on bug bounty. This skill covers race conditions, price manipulation, workflow bypass, coupon/referral abuse, negative values, and state machine attacks. These require human reasoning, not automation. For specific exploitation techniques (payment precision/overflow, captcha bypass, password reset flaws, user enumeration), load the companion SCENARIOS.md. For the workflow approach itself (modeling → state machine → attack-surface matrix → human judgement) load METHODOLOGY.md. For the per-module check items load CHECKLIST.md.

Companion files

File When to load
METHODOLOGY.md Need the 5-phase workflow, attack-surface 5×N matrix, human-judgement decision tree
CHECKLIST.md Going through a target module-by-module (login / register / payment / IDOR / privacy) and want every line item with why+verify
SCENARIOS.md Drilling deeper into payment precision/overflow, captcha bypass, password reset, enumeration, frontend bypass

Extended Scenarios

Also load SCENARIOS.md when you need:

  • Payment precision & integer overflow attacks — 32-bit overflow to negative, decimal rounding exploitation, negative shipping fees
  • Payment parameter tampering checklist — price, discount, currency, gateway, return_url fields
  • Condition race practical patterns — parallel coupon application, gift card double-spend with Burp group send
  • Captcha bypass techniques — drop verification request, remove parameter, clear cookies to reset counter, OCR with tesseract
  • Arbitrary password reset — predictable tokens (md5(username)), session replacement attack, registration overwrite
  • User information enumeration — login error message difference, masked data reconstruction across endpoints, base64 uid cookie manipulation
  • Frontend restriction bypass — array parameters for multiple coupons (couponid[0]/couponid[1]), remove disabled/readonly attributes
  • Application-layer DoS patterns — regex backtracking, WebSocket abuse

Read the full file on GitHub · 712 lines

Files

What ships with it

3 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 5d ago First seen · 712 lines · 37 tokens per session scan A 3e2c2bfc060b

Subscribe to this mod's changes

business-logic-vulnerabilities is a skill published in the GitHub repository miru-zero/zero-brain (0 stars, last pushed 18d ago), licensed MIT. It adds 37 tokens to every session and 7,606 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). It is 98% identical to business-logic-vulnerabilities, differing in 4 lines, and is treated as a copy.

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