MSDN Documentation

SQL Injection

SQL injection is a code injection technique used to attack data-driven applications. Malicious SQL statements are inserted into an entry field for execution. This can lead to unauthorized data access, modification, or even deletion. For example, an attacker might exploit a vulnerable web form to execute commands like:

' OR '1'='1'; --

This simple snippet can bypass authentication by making the `WHERE` clause always evaluate to true.

Unauthorized Access

This threat involves individuals gaining access to database resources they are not authorized to see or manipulate. This can occur through stolen credentials, weak passwords, misconfigured access controls, or exploiting vulnerabilities in the database management system (DBMS) itself.

Data Breaches

A data breach is an incident where sensitive, protected, or confidential data is copied, transmitted, viewed, stolen, or used by an unauthorized individual. These breaches can result from external attacks, internal negligence, or system failures.

Insider Threats

While external attacks are common, insider threats – malicious or unintentional actions by employees, former employees, contractors, or business partners with legitimate access – can be equally damaging. These individuals may exploit their access for personal gain or due to negligence.

Access Control and Authentication

Implement strong authentication mechanisms and role-based access control (RBAC). Ensure that users and applications have only the minimum necessary privileges to perform their tasks. Regularly review and revoke access for users who no longer require it.

Encryption

Encrypt sensitive data both at rest (while stored in the database) and in transit (while being transmitted over networks). This ensures that even if data is intercepted or accessed unauthorizedly, it remains unreadable.

Example: Using SSL/TLS for network connections and Transparent Data Encryption (TDE) for data files.

Auditing and Monitoring

Enable comprehensive auditing to track all significant database activities, including login attempts, data modifications, and schema changes. Regularly review audit logs for suspicious patterns and anomalies. Implement real-time monitoring and alerting systems.

Regular Patching and Updates

Keep your DBMS and related software up to date with the latest security patches and updates. Vendors frequently release patches to address newly discovered vulnerabilities.

Principle of Least Privilege

Grant users and applications only the permissions they absolutely need. Avoid using shared accounts or granting excessive administrative privileges. This limits the potential damage if an account is compromised.

Secure Coding Practices

For applications interacting with the database, follow secure coding practices to prevent vulnerabilities like SQL injection. Use parameterized queries or prepared statements instead of dynamically constructing SQL queries.

Example of parameterized query:

SELECT * FROM users WHERE username = @username AND password = @password;

Database Firewalls

Database firewalls monitor and filter network traffic between applications and databases, blocking malicious or unauthorized queries.

Data Masking

Data masking involves replacing sensitive data with fictitious but realistic data. This is particularly useful for non-production environments (e.g., development, testing) where real sensitive data is not required.