V8 Optimized Fuzzer

A specialized fuzzing framework designed to identify vulnerabilities in the V8 JavaScript engine by targeting high-value test cases.

Features

• Targeted Fuzzing: Focuses on high-value test cases that target specific vulnerability patterns
• Real-time Status Display: AFL-like status screen showing fuzzing progress, current test case, and results
• Comprehensive Crash Analysis: Detailed crash reports with type classification
• Test Case Minimization: Automatically reduces crashing test cases
• Resume Capability: Pause and resume fuzzing sessions
• Resource Management: Monitors system resources during long fuzzing sessions

Performance Note

⚠️ Please be patient during test case generation and execution. The fuzzer creates complex JavaScript test cases that may take time to generate and process, especially during initial setup. The status display will show you what's happening in real-time.

Status Display

The fuzzer features a real-time status display that shows:

• Process Timing: Current runtime and estimated remaining time
• Overall Results: Iterations, total executions, and execution speed
• Findings: Crashes and interesting cases found
• Current Operation: The test case currently being executed, its type, and the result of the last test

This display updates regularly during fuzzing, providing immediate visibility into the fuzzing process.

Getting Started

See QuickStart.md for a quick guide to get up and running.

Documentation

For complete documentation, see Documentation.md.

Components

The fuzzer consists of several modular components:

• optimized_fuzzer.sh: Main fuzzing script
• utils.sh: Utility functions
• high_value_test_cases.sh: Test case generation
• analyze_results.sh: Results analysis tool

Targeted Vulnerability Patterns

The fuzzer specifically targets vulnerability patterns including:

• JIT Type Confusion
• Array Bounds Bypass
• Object Shape Transitions
• Prototype Pollution
• WebAssembly Memory Access
• Function JIT Deoptimization
• Regular Expression Complexity
• Property Access IC Confusion
• Typed Array Out-of-Bounds

Usage Examples

Basic Usage

./optimized_fuzzer.sh

Resume a Previous Session

./optimized_fuzzer.sh --resume

Enable Verbose Output

./optimized_fuzzer.sh --verbose

Analyze Results

./analyze_results.sh

Requirements

• Linux environment (Ubuntu 18.04+ recommended)
• V8 built with Address Sanitizer (ASAN)
• Basic JavaScript corpus files

License

MIT License

Acknowledgments

• The V8 team for their excellent JavaScript engine
• The fuzzing community for their research and tools