What is Code Injection?
Code injection is a critical web security vulnerability that allows attackers to inject malicious code into a seemingly legitimate website or application. This injected code is then executed by the server processing the request, unknowingly granting the attacker the power to manipulate data, steal sensitive information or even take control of the system.
How it works_
Code Injection vulnerabilities arise when user input isn’t properly validated and sanitised before being processed by the application. Attackers can exploit these weaknesses by crafting specially crafted input that includes malicious code. Here’s a simplified breakdown:
- Vulnerable input field: An attacker finds a form or other input field where they can inject code.
Malicious Code Injection: The attacker injects malicious code disguised as regular user input (e.g., login credentials, search queries). - Server-side processing: The application processes the user input without proper validation, allowing the injected code to be interpreted and executed.
- Compromised system: The malicious code can then perform various actions depending on the attacker’s intent, such as stealing data, modifying content or taking control of the server.
Types of code injection_
There are several common types of code injection vulnerabilities, each targeting a specific processing language:
- SQL injection (SQLi): Targets vulnerabilities in database queries, allowing attackers to manipulate data, steal sensitive information or even disrupt database operations.
- Cross-Site Scripting (XSS): Injects malicious scripts into web pages, enabling attackers to steal user sessions, redirect users to phishing sites or deface the website.
- Command injection: Exploits vulnerabilities in applications that execute system commands. Attackers can use this to gain unauthorised access to the server, install malware or delete critical files.
Key components_
- Vulnerable input field: Any part of an application where users can submit data is a potential entry point for code injection attacks.
- Injection point: The specific location within the application code where the user input is processed and interacts with the backend system (e.g., database, operating system).
- Payload: The malicious code injected by the attacker, designed to achieve a specific goal.
- Sanitisation: The process of removing or filtering out any malicious code from user input before it’s processed by the application.
How Microsoft protects against code injection_
- Microsoft Defender for Cloud: This cloud-based security solution offers vulnerability scanning capabilities that can help identify potential code injection vulnerabilities within web applications deployed on Azure.
- Static Application Security Testing (SAST) Tools: Microsoft integrates with various SAST tools that can analyse application code and detect potential code injection vulnerabilities during the development phase.
