Prototype Pollution Scanner
Detects JavaScript prototype pollution vulnerabilities.
What is Prototype Pollution?
Prototype Pollution is a JavaScript vulnerability where attackers can modify Object.prototype or other prototype chains through malicious input. When properties are added to base prototypes, they become accessible on all objects, potentially enabling XSS, denial of service, or remote code execution depending on how the polluted properties are used.
Why is This Important?
Prototype pollution affects both client-side JavaScript and Node.js applications. Server-side pollution can lead to RCE in some frameworks. Client-side pollution enables DOM XSS and other attacks. The vulnerability is subtle—developers don't expect user input to affect object prototypes.
How It Works
1. Attack Surface Mapping
Identifies complex attack vectors including race conditions, desync points, and logic flaws in your application.
2. Advanced Exploitation
Executes sophisticated attack techniques that bypass traditional security controls and detection mechanisms.
3. Impact Assessment
Demonstrates real-world impact with detailed exploitation chains and business risk analysis.
Key Capabilities
Expert-level security testing for sophisticated vulnerabilities that evade traditional scanning tools.
- Race condition and timing attack detection
- Request smuggling and desync analysis
- Business logic flaw identification
- Chained exploit development
- Protocol-level vulnerability testing
Frequently Asked Questions
How does prototype pollution work?
Vulnerable code like merge(target, source) that recursively copies properties may process {"__proto__":{"isAdmin":true}}. This sets Object.prototype.isAdmin = true. Now every object's .isAdmin returns true, potentially bypassing authorization checks.
What functions commonly cause prototype pollution?
Risky patterns: recursive merge/extend functions, deep clone operations, property assignment using bracket notation with user-controlled keys, JSON parsing into existing objects, and libraries like lodash (older versions), jQuery extend, and similar utility functions.
What's the impact of prototype pollution?
Impacts include: denial of service (pollute properties that break functionality), XSS (pollute innerHTML-like properties), authentication bypass (pollute permission checks), RCE in Node.js (pollute properties used in command execution), and affecting any code that checks prototype-inherited properties.
How do I prevent prototype pollution?
Prevention: use Object.create(null) for user-controlled data, freeze prototypes (Object.freeze(Object.prototype)), validate property names against __proto__, constructor, prototype, use Map instead of objects for user data, and update vulnerable libraries.
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