A03: Injection

Injection vulnerabilities are a broad class of attacks that allow an attacker to send untrusted data to an interpreter as part of a command or query. This can result in the execution of unintended commands or the unauthorized access of data.

Types of Injection

• SQL Injection (SQLi): Injecting malicious SQL queries into an application's database.
• Cross-Site Scripting (XSS): Injecting malicious scripts into a web application, which are then executed in the browsers of other users.
• Command Injection: Injecting operating system commands into an application.
• LDAP Injection: Exploiting applications that use LDAP to access and manipulate directory information.
• NoSQL Injection: Injecting malicious code into NoSQL databases.

Mitigation Strategies

• Input Validation and Sanitization: The most effective way to prevent injection attacks is to validate and sanitize all user-supplied input.
• Use of Parameterized Queries (Prepared Statements): For SQL injection, parameterized queries should always be used to separate code from data.
• Output Encoding: For XSS, all user-supplied data should be properly encoded before it is displayed in the browser.
• Principle of Least Privilege: The application should run with the minimum level of privileges necessary to perform its function.

Injection attacks have been a major threat to web applications for many years, and they continue to be a prevalent problem. By following secure coding practices and implementing a defense-in-depth strategy, you can significantly reduce the risk of injection vulnerabilities.