Hunt Race Condition
Hunting skill for race condition vulnerabilities.
Install
npx skills add Zyrexnn/Cybermes --skill hunt-race-condition -g -a claude-code -y- Repository
- Zyrexnn/Cybermes987
- Category
- Security
- Updated
- 3d ago
- License
- Apache-2.0
- Context cost
- Mediumabout 3,000 tokens
- Runs scripts
- No, instructions only
What it does
Hunting skill for race condition vulnerabilities. Built from 12 public bug bounty reports including modern HTTP/2 single-packet attack cases (James Kettle DEF CON 2023 "Smashing the State Machine"; RyotaK / Flatt Security 10,000-request first-sequence-sync expansion 2024). Covers coupon double-redemption, gift-card double-spend, MFA-OTP-validate race, account-create race, faucet/crypto token double-mint, email-activation race, vote/upvote inflation, password-reset token race, rate-limit bypass via concurrent requests. Use when hunting race conditions, TOCTOU bugs, MFA-bypass-via-timing.
Firing a race, two primitives (tooling-agnostic)
Winning a race needs requests that arrive in the same narrow window, sequential sends never
work. Use a single-packet / synchronized-send tool: Burp Repeater "Send group in parallel"
(HTTP/2 single-packet attack), Turbo Intruder (engine=Engine.BURP2, gate sync), or any
client that can flush N requests simultaneously. Two shapes:
- Identical-copies race, fire N IDENTICAL copies of one request at once (limit-overrun: double-spend a coupon/gift-card, exceed a one-per-user quota). Success = ≥2 of the N return 2xx.
- Different-requests race (partial construction), fire a LIST of DIFFERENT requests in one
synchronized window, repeated over several rounds. For register-then-confirm / TOCTOU races
where the object exists in a usable state mid-creation. Example (email-verification bypass, register an arbitrary email, then confirm it through the construction window with a blank token):
Get a fresh CSRF fromRequest A: POST /register body: csrf=<csrf>&username=hacker&email=anything@exploit.net&password=pw Request B: GET /confirm params: token= (empty) Fire A and B together, repeat ~20 rounds.GET /registerfirst, then fire the batch. After it succeeds, log in as the new account and perform the objective (e.g. a state-changing admin action such as deleting a user). The blank-token confirm wins during the window where the user row exists but its verification token isn't set yet.
Crown Jewel Targets
Race conditions are high-severity findings because they break financial, access control, and integrity assumptions that defenders rarely stress-test. Highest payouts come from:
