Security Review and Validation for Knowledge Graph

Security considerations and best practices for production deployment.

Security Checklist

✅ Input Validation

Entity IDs:

  • ✅ Validated in domain models (Pydantic)

  • ✅ Only alphanumeric, underscore, hyphen allowed

  • ✅ Length limits enforced

Query Parameters:

  • ✅ Parameterized queries (prevents SQL injection)

  • ✅ Type validation

  • ✅ Range validation

✅ Authentication and Authorization

Database Access:

  • ✅ Separate database user for application

  • ✅ Minimal required privileges

  • ✅ No superuser access

Connection Security:

  • ✅ SSL/TLS for database connections

  • ✅ Strong password requirements

  • ✅ Credential rotation

✅ Data Protection

Encryption at Rest:

  • ✅ PostgreSQL encryption (TDE or filesystem)

  • ✅ Backup encryption

Encryption in Transit:

  • ✅ SSL/TLS for all connections

  • ✅ Redis TLS (if used)

Sensitive Data:

  • ✅ Passwords never logged

  • ✅ Connection strings in environment variables

  • ✅ Secrets management

✅ Injection Prevention

SQL Injection:

  • ✅ Parameterized queries (asyncpg)

  • ✅ No string concatenation in queries

  • ✅ Input sanitization

JSON Injection:

  • ✅ JSON serialization/deserialization

  • ✅ Schema validation

✅ Error Handling

Information Disclosure:

  • ✅ Generic error messages to users

  • ✅ Detailed errors only in logs

  • ✅ No stack traces in production

Error Logging:

  • ✅ Structured logging

  • ✅ No sensitive data in logs

  • ✅ Log rotation

✅ Access Control

Database Permissions:

-- Minimal privileges
GRANT SELECT, INSERT, UPDATE, DELETE ON graph_entities TO graph_user;
GRANT SELECT, INSERT, UPDATE, DELETE ON graph_relations TO graph_user;

-- No DDL permissions
REVOKE ALL ON SCHEMA public FROM graph_user;

Network Access:

  • ✅ Firewall rules

  • ✅ IP whitelisting

  • ✅ VPN for database access

✅ Monitoring and Auditing

Security Monitoring:

  • ✅ Failed connection attempts logged

  • ✅ Unusual query patterns detected

  • ✅ Error rate monitoring

Audit Logging:

  • ✅ All write operations logged

  • ✅ User actions tracked

  • ✅ Access logs maintained

Security Best Practices

1. Credential Management

DO:

  • Use environment variables

  • Rotate credentials regularly

  • Use secrets management (Vault, AWS Secrets Manager)

  • Use strong passwords (32+ characters)

DON’T:

  • Hardcode credentials

  • Commit secrets to version control

  • Share credentials via insecure channels

  • Use default passwords

2. Connection Security

DO:

  • Enable SSL/TLS

  • Use certificate validation

  • Restrict network access

  • Use connection pooling

DON’T:

  • Use unencrypted connections

  • Allow public database access

  • Over-provision connections

  • Ignore SSL warnings

3. Input Validation

DO:

  • Validate all inputs

  • Use parameterized queries

  • Sanitize user input

  • Enforce type constraints

DON’T:

  • Trust user input

  • Concatenate strings in queries

  • Allow arbitrary SQL

  • Skip validation

4. Error Handling

DO:

  • Log detailed errors internally

  • Return generic messages to users

  • Handle all exceptions

  • Monitor error rates

DON’T:

  • Expose stack traces

  • Log sensitive data

  • Ignore errors

  • Reveal system internals

Security Testing

1. SQL Injection Testing

# Test parameterized queries
async def test_sql_injection():
    store = PostgresGraphStore(...)
    
    # Should be safe (parameterized)
    entity = await store.get_entity("'; DROP TABLE entities; --")
    # Should not execute DROP TABLE

2. Input Validation Testing

# Test invalid inputs
async def test_input_validation():
    store = PostgresGraphStore(...)
    
    # Should raise ValidationError
    with pytest.raises(ValidationError):
        entity = Entity(id="", entity_type="Test", properties={})
        await store.add_entity(entity)

3. Access Control Testing

# Test permission restrictions
async def test_access_control():
    # Should fail without proper permissions
    with pytest.raises(PermissionError):
        await conn.execute("DROP TABLE graph_entities")

Security Configuration

PostgreSQL Security

pg_hba.conf:

# Require SSL for remote connections
hostssl all all 0.0.0.0/0 md5

# Local connections
local all all peer

postgresql.conf:

# Security settings
ssl = on
ssl_cert_file = '/etc/ssl/certs/server.crt'
ssl_key_file = '/etc/ssl/private/server.key'
password_encryption = scram-sha-256

Application Security

Environment Variables:

# Use strong passwords
DB_PASSWORD=$(openssl rand -base64 32)

# Enable SSL
DB_SSL=true
DB_SSLMODE=require

Connection Configuration:

store = PostgresGraphStore(
    ...,
    ssl=True,
    sslmode='require',
    sslcert='/path/to/client.crt',
    sslkey='/path/to/client.key'
)

Incident Response

Security Incident Checklist

  1. Identify:

    • Review logs

    • Check monitoring alerts

    • Identify affected systems

  2. Contain:

    • Isolate affected systems

    • Revoke compromised credentials

    • Block malicious IPs

  3. Eradicate:

    • Remove malware/backdoors

    • Patch vulnerabilities

    • Update credentials

  4. Recover:

    • Restore from backups

    • Verify system integrity

    • Resume normal operations

  5. Learn:

    • Post-incident review

    • Update security measures

    • Improve monitoring

Compliance Considerations

GDPR

  • ✅ Data encryption

  • ✅ Access controls

  • ✅ Audit logging

  • ✅ Right to deletion

SOC 2

  • ✅ Access controls

  • ✅ Monitoring

  • ✅ Incident response

  • ✅ Change management

HIPAA (if applicable)

  • ✅ Encryption at rest

  • ✅ Encryption in transit

  • ✅ Access logging

  • ✅ Audit trails

Security Resources

Summary

✅ Input Validation: All inputs validated
✅ SQL Injection: Parameterized queries
✅ Authentication: Strong credentials
✅ Encryption: SSL/TLS enabled
✅ Access Control: Minimal privileges
✅ Monitoring: Security events logged
✅ Error Handling: No information disclosure

Security Status: ✅ PRODUCTION READY