authbypass-authentication-flaws

1# SKILL: Authentication Bypass — Expert Attack Playbook
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3> **AI LOAD INSTRUCTION**: Expert authentication bypass techniques. Covers SQL injection-based login bypass, password reset flaws, token predictability, account enumeration, brute force bypass, and multi-factor auth bypass. Distinct from JWT/OAuth (covered in ../jwt-oauth-token-attacks/SKILL.md). Focus on the login mechanism itself.
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5## 0. AUTHORIZED CREDENTIAL TEST PLANNING
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7After reducing routing entries, default credentials, username variants, port focus, and wordlist sizing are handled here in one place.
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9### Service-first tiny sets
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11| Service Type | First Usernames | First Passwords |
12|---|---|---|
13| phpMyAdmin | `root`, `admin` | empty, `root`, `phpmyadmin`, `admin` |
14| FTP | `ftp`, `admin`, `test` | empty, `ftp`, `admin`, `123456` |
15| SSH | `root`, `admin`, service account names | `root`, `admin`, seasonal variants |
16| MySQL | `root`, `mysql` | empty, `root`, `mysql` |
17| Tomcat / Java admin | `tomcat`, `admin`, `manager` | `tomcat`, `admin`, `s3cret` |
18| WebLogic | `weblogic`, `admin` | `weblogic`, `welcome1`, `admin` |
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20### Username classes
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22| Class | Examples |
23|---|---|
24| Generic admins | `admin`, `administrator`, `root`, `test`, `guest` |
25| Support / ops | `dev`, `ops`, `sysadmin`, `service`, `backup` |
26| Name-based | `firstname`, `lastname`, `f.lastname`, `first.last` |
27| Mail-derived | left side of corporate email formats |
28| Product-based | `tomcat`, `weblogic`, `jenkins`, `gitlab` |
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