Understanding Injection Attacks and How to Avoid Them

In this article:
Subscribe to our blog:

In 2017, attackers wreaked havoc for 76 days before Equifax finally discovered the breach. Several security lapses had allowed attackers to access the social security numbers, addresses, credit card information, driver’s license numbers, and other sensitive information of over 143 million customers. 

The cost of recovery? $1.38 billion.

The breach was caused by several vulnerabilities, including an unpatched version of Apache Struts software that allowed hackers to use an injection attack.

From Equifax and WooCommerce to Fortnite, companies in every industry can be victims of injection attacks. Understanding the mechanics of injection attacks and how to prevent them is crucial for any organization. Robust application security measures, such as proper input validation, use of parameterized queries, and regular security testing, are essential to protecting systems from these highly disruptive vulnerabilities.

What Is an Injection Attack?

This type of attack is not only common but also highly dangerous, consistently ranking at the top of the OWASP Top 10 list. The prevalence of injection attacks is due, in part, to the ease of exploitation combined with the significant damage they can cause. 

Injection attacks occur when an attacker inserts malicious code into a system, tricking it into executing unintended commands. This can result in unauthorized access, data loss, and even full system compromise. Beyond technical impact, the consequences can be devastating—ranging from hefty regulatory fines and loss of customer trust to significant operational disruption.

How Do Injection Attacks Work?

Injection attacks occur when an application improperly handles user input, allowing untrusted data to be passed to an interpreter as part of a command or query. This typically happens when inputs are not validated or sanitized, enabling attackers to manipulate the application's behavior.

Common attack vectors include form fields, URL parameters, and API endpoints. Attackers inject malicious inputs, like code or queries, into these entry points. The application interprets this data as part of legitimate commands, executing unauthorized actions such as accessing databases or running system commands.

Several vulnerabilities can enable these attacks, including improper input handling and the absence of parameterized queries.

Types of Injection Attacks

Injection attacks come in various forms, each targeting different systems and data.

Understanding the different types of injection attacks is crucial for implementing effective security measures and safeguarding systems from unauthorized access, data theft, and system compromise. 

SQL Injection

SQL Injection exploits vulnerabilities in SQL queries, allowing attackers to manipulate database operations by injecting malicious SQL code. This can lead to unauthorized data access, data modification, or even deletion. Common scenarios include bypassing login screens or extracting sensitive information from databases.

Command Injection

Command Injection occurs when user input is passed directly to system commands. Attackers can execute arbitrary commands on the host OS, potentially taking over the system, deleting files, or launching further attacks.

Cross-Site Scripting (XSS)

XSS attacks inject malicious scripts into web pages, which are then executed by a user’s browser. This can lead to session hijacking, data theft, or defacement of websites. There are three main types:

  • Stored XSS: Malicious scripts are injected and permanently stored on a server, such as in a database or forum post. When other users access the affected page, the script is executed, potentially stealing sensitive data like cookies or session tokens.

  • Reflected XSS: Malicious scripts are injected into a URL or input field and immediately reflected back to the user in the response. This typically occurs through search results or error messages, executing the script in the victim’s browser.

  • DOM-Based XSS: The attack occurs when a malicious script modifies the Document Object Model (DOM) of a webpage. It happens entirely on the client side, altering how the webpage behaves without modifying the server response.

LDAP Injection

LDAP Injection manipulates LDAP queries used to access directory services. Attackers can alter queries to bypass authentication, modify directory entries, or extract sensitive data, posing a threat to systems relying on directory-based authentication.

XML Injection

XML Injection targets web applications that process XML data. By injecting malicious XML content, attackers can manipulate the application's behavior, access unauthorized data, or execute unwanted commands, affecting the integrity of the XML structure.

NoSQL Injection

NoSQL Injection attacks target NoSQL databases by injecting malicious queries. These attacks exploit applications that fail to sanitize inputs, allowing attackers to access, modify, or delete data without authorization.

ORM Injection

ORM Injection manipulates Object-Relational Mapping frameworks by altering SQL queries generated by the ORM layer. This can lead to data corruption, unauthorized access, or the execution of unintended database commands, affecting the integrity and security of the database.

Real-World Injection Attack Examples 

In May 2023, the CL0P hacker group exploited a zero-day SQL injection vulnerability in the MOVEit Transfer web application by Progress Software, affecting over 1,000 organizations and 60 million individuals globally. This breach allowed CL0P to gain unauthorized access to sensitive data, leading to significant disruptions for high-profile victims like British Airways and the BBC.

The attackers used Truebot malware to download additional modules, extending their reach within compromised networks. 

The consequences of this attack were severe. Data breaches of this scale can lead to operational paralysis, hefty regulatory fines, and long-term reputational damage.

For organizations, this is a stark reminder of the importance of securing every layer of their digital infrastructure, from input validation to regular software patching. This breach is a vivid example of the real-world impact injection attacks can have, turning a single vulnerability into a catastrophic breach that disrupts business operations and exposes sensitive information on a massive scale.

How to Prevent Injection Attacks

Preventing injection attacks requires a multi-layered approach to ensure that applications handle user input securely and follow best practices.

Organizations can significantly reduce the risk of these vulnerabilities by validating inputs, using secure coding techniques like parameterized queries, and performing regular security testing. Below, we explore key strategies and techniques to protect against injection attacks.

Input Validation

Proper input validation is the first line of defense against injection attacks. This involves ensuring all user inputs conform to expected formats, such as checking for valid characters, data types, and length.

For example, if a field is meant to capture an email address, it should be validated to ensure it only contains characters typical of an email address format. Rejecting or sanitizing unexpected inputs prevents attackers from injecting malicious code into the system. Implementing strong server-side validation is crucial, as client-side validation can be bypassed.

Parameterized Queries/Prepared Statements

Using parameterized queries, or prepared statements, is fundamental for preventing SQL injection attacks. This method separates user input from the query structure, preventing attackers from altering SQL commands. 

Take a look at this Java example from OWASP. If an attacker were to enter the userID of tom' or '1'='1, the parameterized query would look for a username that matched the entire string tom' or '1'='1, protecting against injections of malicious SQL code.

The code example from OWASP executes the same database query using a PreparedStatement, Java's implementation of a parameterized query.

For example, characters like <, >, and & in HTML, or single quotes (') in SQL, need to be escaped to avoid altering the intended logic of the code. In HTML, < becomes &lt;, and & becomes &amp;. In SQL, single quotes can be escaped by doubling them.

Escaping is particularly important when handling user inputs in contexts like HTML, SQL, or shell commands, where special characters have specific syntactic meanings. Proper escaping ensures that these characters are not interpreted as code, preventing attackers from injecting malicious scripts or commands.

While escaping input is a valuable layer of defense, it should not be relied upon as the sole protection method. It should be combined with other security practices, such as input validation and parameterized queries, to create a robust defense against injection attacks.

Use of ORM and Security Libraries

Object-relational mapping (ORM) frameworks, such as Hibernate or Django ORM, help abstract database interactions, making it harder for attackers to manipulate queries. These frameworks build queries based on safe, predefined methods, reducing the risk of SQL injection. Additionally, security libraries offer pre-built methods for input sanitization, encoding, and escaping, making it easier for developers to implement secure coding practices.

Security Testing

Regular security testing is critical for identifying and addressing injection vulnerabilities throughout the development lifecycle. Static code analysis tools can detect potential issues in source code before deployment, while dynamic testing methods like penetration testing simulate attacks to uncover vulnerabilities in live environments.

Codacy’s automated security testing features can be integrated into the development pipeline to catch issues early, enforce secure coding standards, and provide continuous feedback, significantly reducing the risk of injection attacks.

By implementing these strategies, organizations can effectively protect their systems against the diverse and dangerous range of injection attacks.

Prevent Injection Attacks with Automated Security Scanning

Injection attacks can have devastating consequences, but they are preventable with the right tools and practices. Codacy offers an all-in-one solution for safeguarding your applications by scanning code, enforcing secure coding standards, and detecting vulnerabilities early in development.

With automated security scanning, you can proactively identify and address potential risks before they become critical.

Ready to secure your applications? Start a free trial or book a demo to explore Codacy’s comprehensive security solutions for preventing injection attacks. Visit Codacy Security to learn more.

RELATED
BLOG POSTS

Understanding Server-Side Request Forgery (SSRF) and How to Prevent It
Server-Side Request Forgery (SSRF) is a critical web vulnerability that allows attackers to trick a server into making unauthorized requests to...
OWASP Explained: Secure Coding Best Practices
From global finance to daily communication, software underpins every aspect of modern life. That's why a single data breach can shatter user trust,...
Why OWASP Matters In Modern Web Development
Threats are pervasive in modern software development. These threats don’t just come from 1337 h4x0rz; they come from you. The sophistication of modern...

Automate code
reviews on your commits and pull request

Group 13