What is Code Injection? Types, Prevention & Detection

Understand code injection, its impact on organizations, types, how it works, and explore detection and prevention methods to enhance security.
By SentinelOne January 16, 2025

Code injection attacks are one of the most prominent cybersecurity threats organizations face in the modern digital infrastructure. Such advanced attacks can exploit software vulnerabilities to run code that may lead to data breaches, system takeovers, and significant financial losses. The threat curve extends across domains and branches of the industry, striking not only governmental bodies but e-commerce, too.

Code injection security vulnerabilities are especially critical because they allow attackers to execute arbitrary commands, manipulate a system, and potentially compromise sensitive data. Preventing this security challenge requires a deep understanding of how such attacks work, what their impact assessments look like, and how to prevent them in the first place.

In this technical blog, we will elaborate on code injection attacks, including techniques of the attack and what organizations can do to defend themselves.

What is Code Injection?

Code injection is a type of cyberattack in which attackers exploit vulnerabilities in an application to inject and execute arbitrary code in a target system. The attack fundamentally takes advantage of poor input validation and insecure coding practices that can be exploited to extend beyond the intended functionality of an application to gain access to, manipulate, or export sensitive information.

The attack surface generally consists of several points where user-provided data meets the backend. This can include everything from form input fields, URL parameters, HTTP headers, and even API endpoints. If successful, attackers use these interaction points to insert commands, from SQL queries to system-level commands, that the application executes with its native privileges and permissions.

How Code Injection Can Affect Organizations?

Code injection attacks can be catastrophic for organizations, with potentially large financial, operational, and reputational costs. When exploited, these attacks can open organizations up to compromised data, service outages, compliance failure, and other issues.

The first and most immediate effect is data theft, in which sensitive customer or business data is at risk. Attackers can exfiltrate credentials for logging in, payment details, and proprietary data, which can then be sold on the dark web or used for further attacks.

In addition to data loss, code injection attacks can be highly disruptive to operations. In case a server or system is compromised, it may be rendered inoperable, causing downtime and business continuity issues. For industries dependent on uptime, like e-commerce and healthcare, these interruptions can equate to lost revenue and decreased customer trust.

Different Types of Code Injection

There are a number of types of code injection, each exploiting unique weaknesses of implementations. This is important for preventing and mitigating them effectively.

1. SQL Injection

SQL Injection is an attack on applications that communicate with relational databases. In SQL injection attacks, attackers modify SQL queries by inputting malicious data into forms, URLs, or headers to form queries that the application executes, leading to undesirable commands. This leads to unauthorized access to data, disruption of the database, or complete control of the backend.

SQL Injection may be an attack vector that has existed for many years, but it is definitely alive and out there, which is primarily due to improper input validation and legacy coding styles.

Organizations that are still overly dependent on legacy systems or do not sanitize user’s inputs are at a greater risk of exploitation.

2. Command Injection

This vulnerability enables attackers to run arbitrary commands on the host server by injecting malicious inputs, which can lead to the complete takeover of the system. An example of a crafted input could be rm -rf /, which would delete important files on a server.

Command Injection is especially harmful to environments where applications directly call the operating system processes. The fallout can vary from minor inconveniences to full system hijacks and is usually accompanied by significant downtime and lost revenue.

3. Cross-Site Scripting (XSS)

XSS is an abbreviation for cross-site scripting. In this method, attackers inject malicious scripts into a web page, and those scripts are viewed by other users. These scripts can run within the victim’s browser, enabling attackers to steal session cookies, deface websites, or deliver malware.

Common examples of XSS can be found in common comment sections, chat applications, or search bars.

There are three types of XSS attacks: Stored, Reflected, and DOM-based; respectively, they save the malicious script on the server, send the script as part of a URL, and manipulate the Document Object Model (DOM) in the browser. XSS continues to be a serious threat to web apps due to its large attack surface.

4. LDAP Injection

LDAP Injection is an attack against Lightweight Directory Access Protocol (LDAP) queries (LDAP is often used for authentication and directory lookups). An attacker can manipulate input fields to execute arbitrary LDAP statements to bypass authentication or escalate privileges. For instance, an intruder could modify an LDAP query to give himself admin-level privileges.

LDAP Injection is particularly perilous in enterprise environments, as LDAP is commonly used to manage sensitive user accounts and permissions.

5. XML Injection

Another common type of injection attack is called XML Injection, which consists of messing with the XML data or queries to change application logic. As a result, attackers can inject malicious XML payloads to retrieve sensitive information, bypass authentication, or even cause denial-of-service attacks.

This kind of attack vector is particularly relevant to applications that use XML for communication or configuration, such as SOAP-based APIs or older systems. This is because XML structures are often very complex, so detecting these types of attacks is a difficult mitigation task.

How Does Code Injection Work?

Code injection attacks take advantage of vulnerabilities in applications where user input is expected. Attackers can use injection attacks by adding malicious code to input fields or queries, allowing them to execute unauthorized commands and compromising the application’s behavior. SQL injection attacks often succeed due to poor input validation, incorrect encoding, or insecure coding practices.

For example, when a user supplies input into an application (entering data in a form or passing parameters through a URL), the application processes that input to perform specific actions. The login form, for example, validates credentials by querying the database. When the input is not sanitized, an attacker can then inject malicious code, changing the intended query.

The common workflow flow of a code injection attack is as follows:

  1. Reconnaissance: The attackers study the application to find entry points of vulnerability in the application. This can include analyzing input fields, application programming interfaces (API), or backend system query parameters.
  2. Injection: An attacker crafts and injects malicious code into these input points. This code can be SQL queries, system commands, scripts, etc.
  3. Execution: The injected code executes as the application cannot differentiate between the malicious input and the normal input. It may result in reading sensitive data, changing system files, or elevating powers.
  4. Post-Attack Behavior: If they succeed, attackers can then extract data, plant malware, or create backdoors to be able to come back later.

For instance, in SQL Injection it would look like an attacker entering into a username field ' OR '1'='1 (example payload). When this input is executed as part of a database query without proper sanitization, the SQL command that results can defeat authentication and allow access to restricted content.

Detection Mechanisms for Code Injection Attacks

Detecting code injection attacks is essential to reduce its effects. To find code injection vulnerabilities, organizations must take a layered approach, fundamental to which will be the mix of automated tools and manual review.

1. Static Analysis

Static analysis tools analyze source code to identify insecure coding practices and potential injection points before deployment of the application. These tools check code for hardcoded secrets and entry points for various vulnerabilities, like unsanitized user inputs or other incorrect handling of database queries. Static analysis identifies issues early in the development cycle, which reduces the attack surface.

Static analysis is a good approach for catching vulnerabilities during development but needs frequent updates of its vulnerability database/queries so that it detects the latest vulnerabilities. Integration into CI/CD pipelines for continuous scanning is another of its advantages.

2. Dynamic Analysis

Dynamic analysis tools perform tests against an application in real-time, replicating real-world attacks to find vulnerabilities. Static analysis is limited to looking for known patterns and will often miss application-specific vulnerabilities that may only be found through thorough application testing, such as misconfigured servers. They engage with the application to some degree, so they are useful for discovering code injection vulnerabilities.

Dynamic analysis is complementary to static analysis and concentrates on runtime behaviors. On the other hand, it demands resources and expertise to cover all aspects of real-world conditions in a more realistic manner, which takes time and effort to account for all possible edge cases.

3. Runtime Protection

Runtime application self-protection (RASP) solutions watch an application’s behavior in real-time to identify and stop suspicious activities. These systems can detect code violations in real time by looking at patterns, like an unfamiliar structure of a query or suspicious system commands. RASP introduces a layer of security inside the app itself, thereby eliminating dependence on external monitoring systems.

RASP is especially helpful in production environments where there is an immediate need to react to live threats. Its adaptability to changing threats makes it a cornerstone of contemporary defensive strategies.

4. Input Validation

One of the most basic but effective mechanisms to detect this is strict input validation. Determining what an input should look like (for example, a hexadecimal or a longer input) restricts the chance of a malicious payload being processed. This is commonly paired with automated tools to improve security measures.

Input validating should be implemented across all user inputs to retrain loopholes such as those specified on hidden fields, query parameterization, and API requests. Robust input validation also lightens the load on additional security layers.

How to Prevent Code Injection Attacks?

To avoid code injection attacks, you must adopt secure coding practices, use input sanitization, and implement layered defenses. To reduce the risk of injection vulnerabilities, organizations should implement best practices throughout the software development lifecycle.

Input Sanitization

This practice prevents malicious inputs by filtering out dangerous characters from all user input before it is processed. Developers can neutralize potential attack vectors such as SQL commands or script injections simply by stripping unwanted characters or patterns. This step makes sure only safe and expected values reach the backend systems

To implement input sanitization properly, developers need to ensure that they identify all potential inputs, query parameters, cookies, and HTTP headers and sanitize them as they go. It is a strong first line of defense when paired with other security measures.

Parameterized Queries

Preparing statements (also referred to as parameterized queries) are used to secure interaction with the database by delimiting user input from query logic. Parameterized queries are different from the traditional query technique in which there is a direct concatenation of input and raw query. In the parameterized query, the input is treated as data, and not executable, thus avoiding SQL injection attack.

Parameterized queries, for instance, use placeholders as ”?” instead of actual data when writing a query such as SELECT * FROM users WHERE name = 'input', and the database securely binds user input to those placeholders. It can help you avoid injection by using dynamic queries.

Output Encoding

Output encoding is a context-sensitive encoding that encodes user content such that malicious code is not executed as a species of small scripts executed in the browser. For example, special characters such as < or > are converted to their encoded equivalents, like &lt; and &gt;, ensuring they are treated as text instead of executable code.

This technique is very useful in preventing Cross-Site Scripting (XSS) attacks. Using output encoding frameworks, such as OWASP’s ESAPI or even built-in libraries within modern programming languages, can significantly help mitigate this risk.

Content Security Policy (CSP)

Content Security Policy is a security mechanism that is implemented in the browser that prevents the execution of unauthorized scripts on a webpage. CSP (Content Security Policy) helps to mitigate XSS attacks by specifying a strict set of rules about how your website behaves, such as whether or not scripts can be included from untrusted sources.

CSP is most effectively used in conjunction with good input sanitation and output encoding. All policy details are then regularly updated to include new dependencies or changes in application structure so they remain effective.

How SentinelOne Can Help?

SentinelOne offers a complete cyber security umbrella with advanced capabilities to detect, prevent, and respond to complex cyber-security threats in real-time.

Runtime Protection Features

Runtime Application Self-Protection (RASP) from SentinelOne protects applications by observing their behavior while they are running. It recognizes and blocks anomalous activities.

Attack Detection Capabilities

SentinelOne uses AI-based algorithms to detect patterns and behaviors related to code injection attacks. From confusing query shapes to odd system commands through potential adjustments in input, SentinelOne offers timely detection, limiting the window that attackers have to exploit weaknesses.

Automated Response Actions

If an active threat is detected, SentinelOne aims to mitigate the attack, isolating the application or system that would minimize the attack spread. This limits damage and stops lateral movement across the network. Also, automated remediation tools can roll back unauthorized changes to return systems to a state before the attack.

Real Time Monitoring

SentinelOne provides application, server, and endpoint visibility and real-time monitoring. This real-time monitoring allows organizations to identify and mitigate suspicious behavior before it transitions into a major attack.

Conclusion

Code injection attacks are among the most prevalent and dangerous threats in the world of cybersecurity. Attackers can leverage these vulnerabilities in applications to gain unauthorized access, steal sensitive data, and disrupt operations. SQL Injection and Command Injection attacks emphasize the importance of rigorous input validation to prevent potential vulnerabilities.

To defend against these threats, organizations need to take a multi-tiered approach to security. These techniques include input sanitization (cleaning/validating user input), parameterized queries, output encoding, and principles like least privilege. Security tools like SentinelOne provide an added layer of protection through real-time monitoring, automated response, and advanced defense capabilities at runtime.

FAQs

1. What is a code injection attack?

A code injection attack is a type of cyberattack where malicious code is inserted into an application to alter its behavior. It often exploits vulnerabilities caused by poor input validation, allowing attackers to steal data, execute unauthorized commands, or disrupt systems.

2. What is the difference between code injection and SQL injection?

Code injection is a broad term covering any attack where malicious code is executed in an application, while SQL injection specifically targets databases by manipulating SQL queries to access or modify data.

3. How can code injection attacks be detected?

Code injection attacks can be detected using tools like static and dynamic analysis, runtime monitoring, and behavior analysis. These methods identify suspicious patterns or behaviors that indicate malicious activity.

4. How can developers protect applications from code injection?

Developers can prevent code injection by implementing secure coding practices, such as input sanitization, parameterized queries, output encoding, and using Content Security Policies (CSP) to restrict unauthorized actions.

5. Can web application firewalls (WAF) stop code injection attacks?

Yes, WAFs can help stop code injection attacks by filtering and blocking malicious traffic before it reaches the application. However, they should be used alongside other security measures for comprehensive protection.

6. How can code injection vulnerabilities be mitigated in cloud environments?

Mitigating code injection in cloud environments involves proper input validation, secure API configurations, least privilege access, and regular security assessments to identify and address vulnerabilities.

7. What are the remediation steps after a code injection attack?

Remediation steps include isolating the affected system, analyzing logs to identify the attack vector, patching the vulnerability, restoring from secure backups, and conducting a post-incident review to strengthen defenses.

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