Cybersecurity Awareness Month: How to mitigate an SQL Injection Attack

Oct. 14, 2024
Application security SaaS company Indusface has detailed the potential financial impact of SQL Injection attacks on businesses.

A Structured Query Language (or SQL) injection attack was listed as the third-most critical safety risk to organizations by the OWASP Top 10 and is still a threat to 21% of organizations, costing them millions in recovery and reputational damage each year.1 2Despite this, Google searches in the U.S. for ‘SQL Injection definition’  have surged by 250% in the last 90 days, highlighting the growing prevalence and importance of such attacks.3

In response to this, the application security SaaS company Indusface has detailed the potential financial impact of SQL Injection attacks on businesses. Additionally, they offer best practices to help organizations effectively mitigate the risks associated with such attacks.

How costly can an SQL Injection Attack be for an organization?

Listed as the third critical safety risk to organizations by the OWASP Top 10, SQL injections significantly threaten organizational data security. The impact of an SQL injection attack can be severe as it grants attackers full control over databases, allowing them to manipulate or extract sensitive information. This can result in stolen data being sold on the dark web, causing significant financial and reputational damage.

Additionally, data manipulation can lead to business disruptions and extortion attempts, with some of the largest organizations, including TalkTalk having been victims of an SQL Injection Attack and were fined over £400,000 ($522,750) after 150,000 customers had their data stolen.4

This highlights why developers need to implement robust safeguards to prevent unauthorized access and protect against data breaches.

Venky Sundar, Founder and President of Indusface, outlines how organizations can effectively mitigate the risks associated with an SQL Injection Attack:

“There are many ways to effectively prevent an SQL attack; securing all inputs and server-side processes is the most essential. While it does help to have client-side validation, it is not sufficient against determined attackers. Here’s an 8-step comprehensive approach to prevent and mitigate SQL injection attacks:

1. Implement input validation and proper error handling to secure database interactions.

By validating user input, applications can restrict the data to expected formats and standards, reducing the risk of malicious SQL commands being executed within SQL queries and ensuring that it adheres to predefined criteria such as format, length, and range. Sanitization is different; it removes or encodes potentially harmful characters from the input.

Example (using PHP and filter_var):

$username = filter_var($_POST['username'], FILTER_SANITIZE_STRING);

2. Use parameterized queries and prepared statements to prevent malicious SQL input.

Mitigating SQL injection attacks requires secure coding practices. Developers should use parameterized queries and prepared statements to ensure user inputs are never executed as SQL code.

Another effective coding practice to mitigate the risk of SQL injection is parameterized statements. These separate user inputs from the SQL query, which removes the need for manual escaping, ensuring that user inputs are treated as data, which prevents any potentially malicious code from being executed. The database system identifies placeholders, securing user inputs during execution.

Example (using Python and SQLite):

cursor.execute("SELECT * FROM users WHERE username = ? AND password = ?", (user_input, password_input))

Placeholders (?) are used instead of inserting user inputs directly into the SQL query for values provided later. The query is executed with placeholders as the initial argument and a tuple of actual values (for example, user_input and password_input) as the second. During execution, the database securely binds these inputs as data, not part of the SQL query, preventing any SQL injection attacks.

3. Maintain Applications and Databases.

SQL injection vulnerabilities in applications and databases are frequently discovered and publicly disclosed. To mitigate the risk, organizations must stay informed about vulnerability updates and vendor announcements, ensuring that patches or updates are applied promptly.

To prevent SQL injections, all elements of a web application must be regularly monitored and updated, including database servers, frameworks, libraries, plugins, APIs, and web server software. For organizations facing challenges with timely patching, investing in a patch management solution can help alleviate the workload for IT and development teams by streamlining the update process.

4. Monitor Application and Database Interactions and Communications.

Organizations should implement continuous monitoring of SQL statements in database-connected applications, focusing on activity related to accounts, prepared statements, and stored procedures. This enables the timely detection of rogue SQL statements and vulnerabilities, allowing administrators to mitigate risks by removing unnecessary components.

Integrating machine learning and behavioral analysis through tools like Privileged Access Management (PAM) and Security Incident and Event Management (SIEM) further strengthens protection against SQL injection and other database threats.

5. Deploy Web Application Firewalls (WAFs).

A Web Application Firewall (WAF) serves as a critical layer of security by monitoring and filtering incoming HTTP traffic, which helps identify and block any potential SQL injection attempts and other malicious activities. Through customizable rules, WAFs detect specific attack patterns, providing an additional safeguard for applications.

In organizations facing challenges such as outdated code, resource constraints for testing, and frequent application updates, a WAF can be especially beneficial. Immediate code fixes aren’t always feasible for organizations, so WAFs enable virtual patching, which offers temporary protection against known vulnerabilities while allowing time for proper updates.

They can also log and alert administrators to suspicious activity, providing insights into potential threats and enabling timely responses.

6. Use Stored Procedures In the Database.

Implementing stored procedures can add a layer of protection by isolating the database from direct user interaction, reducing the risk of certain exploitations. Rather than executing SQL code directly on the database, the application triggers stored procedures, which then return the results. Stored procedures also require variable binding, which further enhances security by ensuring user inputs are handled appropriately.

However, it's important to note that stored procedures are not entirely immune to SQL injection vulnerabilities, especially if dynamic SQL generation is employed within the procedure.

7. Regularly patch and update your SQL Servers.

Keeping SQL Servers up to date with the latest cumulative and security patches is essential for maintaining security and system performance. Regular updates reduce vulnerabilities and enhance system stability, but it's critical to test these updates in a non-production environment before deployment to avoid compatibility or performance issues. 

Automated tools like Windows Server Update Services (WSUS) can streamline the update process, though manual testing and troubleshooting remain key practices.

If patching cannot be prioritized immediately, deploy virtual patches on the WAF. These are compensatory controls that buy time for your team until they are ready to patch on code.

By staying current with patches and addressing potential issues proactively, organizations can minimize risks and ensure the ongoing integrity of their SQL Server environments.

8. Educate employees and developers on secure coding practices and attack prevention.

To further mitigate the risks of an SQL injection on your organization, it’s essential to demonstrate to developers the potential impact of SQL injection attacks on both the database and the application. Utilizing tools such as sqlmap or sqlninja can effectively showcase how easily SQL injection vulnerabilities can be exploited to extract data, execute commands, or perform other malicious actions on a database.

Lastly, providing real-world examples of SQL injection attacks that have led to significant data breaches, financial losses, or reputational harm can further underscore the risks.

Methodology:

  1. Indusface set out to uncover the potential financial impact of SQL Injection attacks on businesses.
  2. They also provided best practices to help organizations effectively mitigate the risks associated with such attacks.
  3. Search data was obtained from Google Trends. The data is correct as of the 9th of October 2024.

Citations

[1] OWASP | “A03:2021 - Injection”

[2] Wattlecorp | “The Hidden Cost of Cyber Attacks: What You Don’t See Can Hurt You”

[3] Google Trends | “SQL Injection Definition”

[4] Software Lab | “SQL Injection Examples (2024): The 4 Worst Attacks Ever”