This document provides comprehensive documentation of the security controls implemented in the PISC (Prompt Injection Scanner) application.

Implementation Status: ✓ Complete

Location: api/security_validation.py

Features:

• Input length validation (1-50KB)
• Type validation (must be string)
• Unicode normalization
• Dangerous pattern detection
• Null byte removal
• Special character sanitization

Key Methods:

• validate_input() - Comprehensive validation function
• validate_prompt() - Convenience function for prompt validation
• check_injection_patterns() - Pattern detection
• prompt_validator() - Pydantic validator for API models

Integration:

• Used in ScanRequest model for API input validation
• LLM classifier input validation in llm_classifier.py
• Scanner input validation in scanner.py

Implementation Status: ✓ Complete

Security Headers:

• X-Content-Type-Options: nosniff - Prevents MIME type sniffing
• X-Frame-Options: DENY - Prevents clickjacking
• X-XSS-Protection: 1; mode=block - XSS protection
• Strict-Transport-Security: max-age=31536000; includeSubDomains - HSTS
• Content-Security-Policy: default-src 'self' - CSP

Location: api/main.py:474-481

Error Handling:

• Centralized exception handling with sanitized error messages
• Validation error handler with safe user feedback
• General exception handler with minimal information leakage

Location: api/main.py:429-461

Implementation Status: ✓ Complete

Dependency Management:

Python (Backend):

• requirements.txt - Explicit dependency versions
• Safety tool integration - safety check
• Bandit static analyzer - bandit -r
• Pip audit support - pip-audit

Frontend (React):

• web/package.json with security scripts
• npm audit - Check for vulnerabilities
• npm audit fix - Auto-fix vulnerabilities

Security Scripts:

# Python security checks
python -m pip install -r requirements.txt
python -m safety check
python -m bandit -r api scanner.py llm_classifier.py

# Frontend security checks
cd web
npm audit
npm run check:security

Dependency Verification:

• security_verification.py automatically checks dependencies
• Requirement files include explicit version constraints
• Regular audit process recommended

Implementation Status: ✓ Complete

Secure Logging:

• No sensitive data logging (API keys, passwords, tokens)
• Prompt hashing for log entries
• Truncation of long strings
• JSON structured logging
• Rotating file handlers
• Console and file output support

Location: api/security_logging.py

Key Features:

• SecureJSONFormatter - Sanitizes logs before output
• SecurityLogger - Main logger class with correlation IDs
• log_scan_event() - Scan-specific logging
• log_security_event() - Security event logging
• Sanitization of sensitive data fields

Implementation Status: ✓ Complete

Security Audit Logging:

• Structured security audit events
• Integrity verification with SHA-256 hashes
• Comprehensive event types
• Audit severity levels
• Compliance-friendly format

Location: api/security_audit.py

Audit Event Types:

- AUTH_SUCCESS / AUTH_FAILURE - Authentication events
- ACCESS_DENIED / ACCESS_GRANTED - Authorization events
- REQUEST_RECEIVED / REQUEST_COMPLETED - Request events
- INJECTION_DETECTED / SSRF_ATTEMPT - Security threats
- RATE_LIMIT_EXCEEDED / INVALID_INPUT - API protection
- SCAN_STARTED / SCAN_COMPLETED - Scan operations

Key Methods:

• SecurityAuditLogger.log_event() - Log audit events
• AuditEvent.verify_integrity() - Verify event hash
• Convenience methods for common events (log_auth_success(), log_injection_detected(), etc.)

Implementation Status: ✓ Complete

SSRF Prevention:

• URL validation and allowlist checking
• DNS rebinding protection with caching
• Request timeout enforcement
• IP address blocking (internal networks)
• Allowed hosts configuration

Location: api/security_ssrf.py

Key Features:

• Blocks private/internal IP addresses (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16)
• Blocks localhost and loopback addresses
• Validates API endpoints against known safe hosts
• Default 30-second timeout for requests
• DNS cache with TTL to prevent rebinding attacks

Methods:

• validate_url() - Comprehensive URL validation
• validate_openai_endpoint() - OpenAI-specific validation
• block_internal_ips() - Check if IP is internal
• SSRFProtection class for SSRF protection

Features:

• CORS with restricted origins
• API key authentication
• Rate limiting (60 requests/minute per IP)
• Endpoint protection middleware

Location: api/main.py

Features:

• No sensitive data logging
• Environment variable configuration
• Secret validation on startup
• API key validation

Location: api/main.py, api/security_logging.py

Features:

• Server bind address configuration (localhost by default)
• Request size limits (100KB)
• Production/development environment detection
• Security header middleware

Location: api/main.py, api/run.py

Features:

• API key authentication
• Middleware authentication
• Header-based API key validation
• Public/private endpoint segregation

Location: api/main.py

Verification Tool: security_verification.py

Usage:

# Run full security verification
python security_verification.py

# Expected output:
# ✅ All security controls are properly configured!

What's Verified:

• Environment configuration (API keys, CORS, server settings)
• Security modules importability
• Input validation
• SSRF prevention
• Security logging
• Security audit system
• Dependency security
• Frontend dependencies
• Bandit static analysis

Environment Variables:

# API Configuration (A07)
PISC_API_KEY=your-secure-api-key  # Generate with: python -c "import secrets; print(secrets.token_hex(32))"

# LLM Configuration
OPENAI_API_KEY=your-openai-api-key

# CORS Configuration (A01)
ALLOWED_ORIGINS=http://localhost:5173,http://localhost:3000

# Server Configuration (A05)
HOST=127.0.0.1  # Bind to localhost
PORT=8000

1. Use ENV=development for local testing
2. Generate secure API keys using python -c "import secrets; print(secrets.token_hex(32))"
3. Run security verification before each commit: python security_verification.py

1. Set ENV=production
2. Configure PISC_API_KEY with a secure value
3. Restrict ALLOWED_ORIGINS to specific domains
4. Disable debug mode
5. Use HTTPS
6. Regularly update dependencies
7. Monitor security logs

1. Run dependency audits monthly:
   • Python: python -m pip list --outdated and python -m safety check
   • Frontend: cd web && npm audit
2. Review security logs regularly
3. Update security patterns in api/security_validation.py
4. Test new features with security verification script

Security Events to Monitor:

• auth_failure - Failed authentication attempts
• injection_detected - Prompt injection attempts
• ssrf_attempt - SSRF attempts
• rate_limit_exceeded - Rate limiting triggers
• invalid_input - Invalid input patterns

Audit Log Location: logs/security_audit.log

Response Actions:

1. Identify the source IP address from audit logs
2. Block suspicious IP addresses
3. Analyze the attack pattern
4. Update security patterns if needed
5. Review API keys and secrets

PISC implements comprehensive security controls addressing all OWASP Top 10 (2021) vulnerabilities. The security architecture includes:

• Preventive Controls: Input validation, SSRF protection, authentication
• Detective Controls: Security audit logging, pattern detection
• Corrective Controls: Error handling, rate limiting
• Documentation: Complete security documentation and verification

Regular security audits and maintenance are essential to maintain the security posture.