Auth Bypass Tester

Auth Bypass Tester is a skill for Claude Code, Codex from PramodDutta/qaskills. It costs 27 tokens per session (11,108 once invoked), scanned A, original, MIT.

A guide for testing whether an application correctly checks who a user is and what that user is allowed to do. It covers login sessions, permissions, and signed tokens such as JWTs.

In plain words
What is it for?
Use it to plan or review tests for session hijacking, privilege escalation, JWT tampering, authentication flows, and access-control rules.
Why use it?
It helps find ways users might reach accounts, data, or actions they should not be able to access. It also checks that altered, expired, or misused login tokens are rejected.

Skill for Claude CodeCodex

Which agent this was written for is unclear — built for aider. Also seen: mentions Codex; built for aider; mentions Gemini CLI.

Needs its repository: it reads a path above its own folder, which exists only inside the repository. The line is import { TEST_USERS, ENDPOINT_AUTH_MATRIX, TestUser } from '../fixtures/user-roles';.

Good fit Use it to plan or review tests for session hijacking, privilege escalation, JWT tampering, authentication flows, and access-control rules.

Compare 6 skills from other repositories ↓
Install

Getting it into your agent

It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.

Clone the repo
git clone --depth 1 https://github.com/PramodDutta/qaskills
agentmods
npx agentmods add skills/pramoddutta/qaskills/auth-bypass-tester

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 Auth Bypass Tester

README.md
[![agentmods](https://agentmods.dev/badge/skills/pramoddutta/qaskills/auth-bypass-tester/github.svg)](https://agentmods.dev/skills/pramoddutta/qaskills/auth-bypass-tester)
Your own site
<a href="https://agentmods.dev/skills/pramoddutta/qaskills/auth-bypass-tester"><img src="https://agentmods.dev/badge/skills/pramoddutta/qaskills/auth-bypass-tester/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 Auth Bypass Tester

Your own site · 80×15
<a href="https://agentmods.dev/skills/pramoddutta/qaskills/auth-bypass-tester"><img src="https://agentmods.dev/badge/skills/pramoddutta/qaskills/auth-bypass-tester.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 27 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 11,108 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. 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: 7 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 Privilege Escalation · line 460
    Code accesses credential files (SSH keys, AWS credentials, etc.). This could indicate credential theft attempts.
    Fix: Remove references to credential paths. Use environment variables or secrets managers. For docs, use placeholder paths (e.g., /path/to/config). Never load .env or token files in production code paths.
  • high Tool Misuse · line 121
    Tool parameters are crafted to achieve unintended or unsafe behavior. Parameter abuse can bypass intended safety checks (e.g. shell=True, --force, dangerous glob patterns).
    Fix: Validate all tool parameters against an allowlist. Reject dangerous parameter values (shell=True, --force, -rf /) and use safe defaults.
  • high Tool Misuse · line 126
    Tool parameters are crafted to achieve unintended or unsafe behavior. Parameter abuse can bypass intended safety checks (e.g. shell=True, --force, dangerous glob patterns).
    Fix: Validate all tool parameters against an allowlist. Reject dangerous parameter values (shell=True, --force, -rf /) and use safe defaults.
  • medium Data Exfiltration · line 1104
    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 1190
    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 1199
    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.
  • low Privilege Escalation · line 773
    Skill requests more permissions than appear necessary for its stated functionality. Review if elevated access is justified.
    Fix: Request only the minimum permissions required. Document why each permission is needed. Remove broad permissions like '*' or 'all'.
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 $0.00027 $0.11108
Opus 5 $0.00014 $0.05554
Sonnet 5 $0.00005 $0.02222
Haiku 4.5 $0.00003 $0.01111

Measured 10d ago against content hash 335f134584af, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

Auth Bypass Tester 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 10d 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.

response = await request.fetch(protectedPath, { method: 'OPTIONS' });
seed-skills/auth-bypass-tester/SKILL.md · 1,294 lines

How it starts

The opening of the file, as written. The whole thing — 1,294 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Auth Bypass Tester Skill

You are an expert security tester specializing in authentication and authorization bypass testing. When the user asks you to write, review, or plan auth bypass tests, follow these detailed instructions to systematically identify vulnerabilities in authentication flows, session management, access control enforcement, and token-based security mechanisms.

Core Principles

  1. Defense in depth verification -- Never trust a single layer of authentication. Test that every access point independently verifies identity, authorization, and session validity rather than relying on upstream checks alone.
  2. Least privilege enforcement -- Verify that every endpoint, resource, and action enforces the minimum required permissions. Users should only access what they explicitly need, and the system should deny by default.
  3. Stateless token integrity -- JWTs and other stateless tokens must be cryptographically verified on every request. Test that the server rejects tampered, expired, or algorithmically downgraded tokens without exception.
  4. Session lifecycle completeness -- Test the entire session lifecycle from creation through destruction. Ensure that logout actually invalidates server-side state, that session fixation is impossible, and that concurrent session policies are enforced.
  5. Indirect object reference protection -- Every resource accessed by user-supplied identifiers must verify that the requesting user has authorization to access that specific resource. Predictable IDs without authorization checks are critical vulnerabilities.
  6. Fail-secure behavior -- When authentication or authorization components fail, error out, or encounter unexpected input, the system must deny access rather than granting it. Test edge cases where parsing failures might bypass checks.
  7. Cross-origin and cross-context isolation -- Verify that authentication state cannot be leveraged across unintended origins, subdomains, or application contexts. CSRF protections, SameSite cookie attributes, and CORS policies must be correctly configured.

Read the full file on GitHub · 1,294 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. 10d ago First seen · 1,294 lines · 27 tokens per session scan A 335f134584af

Subscribe to this mod's changes

Auth Bypass Tester is a skill published in the GitHub repository PramodDutta/qaskills (220 stars, last pushed 10d ago), licensed MIT. It adds 27 tokens to every session and 11,108 once invoked, about $0.0001 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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