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hunt-captcha-bypass

Hunt CAPTCHA Bypass — 6 distinct patterns: (1) CAPTCHA field simply omitted from the request (server-side validation absent), (2) CAPTCHA token replayed from a solved challenge (no single-use enforcement), (3) CAPTCHA response accepted on a different endpoint than it was solved on (no binding to action/session), (4) static or predictable CAPTCHA values accepted (e.g. '0', 'null', empty string), (5) audio/accessibility CAPTCHA trivially solvable programmatically, (6) CAPTCHA only enforced after N failures (first N requests bypass it). Detection: intercept a successful form submission, remove the CAPTCHA field entirely, replay — if it still succeeds, server-side validation is absent. Medium severity standalone; High when it removes the only rate-limit gate protecting a login, registration, or payment endpoint.

67

Quality

80%

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SecuritybySnyk

Critical

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tessl review fix ./skills/hunt-captcha-bypass/SKILL.md
SKILL.md
Quality
Evals
Security

Security

2 findings: 1 critical severity, 1 high severity. Installing this skill is not recommended: please review these findings carefully if you do intend to do so.

Critical

E006: Malicious code pattern detected in skill scripts.

What this means

Detected high-risk code patterns in the skill content — including its prompts, tool definitions, and resources — such as data exfiltration, backdoors, remote code execution, credential theft, system compromise, supply chain attacks, and obfuscation techniques.

Why it was flagged

This document explicitly instructs how to bypass CAPTCHA protections (omit fields, replay tokens, use concurrency) and describes resulting abuse (brute force, account farming), indicating clear malicious intent to evade anti-automation controls.

Report incorrect finding
High

W007: Insecure credential handling detected in skill instructions.

What this means

The skill handles credentials insecurely by requiring the agent to include secret values verbatim in its generated output. This exposes credentials in the agent’s context and conversation history, creating a risk of data exfiltration.

Why it was flagged

The skill explicitly instructs capturing a real CAPTCHA token ("g-recaptcha-response") and resubmitting the SAME token value, which requires the agent to read and include sensitive token values verbatim in requests.

Repository
elementalsouls/Claude-BugHunter
Audited
Security analysis
Snyk

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