How to Prevent SQL Injection ?

Preventing SQL Injection Attacks - Key Prevention Methods

Introducing SQL (Structured Query Language) injection is a type of electronic attack where the intruder uses a portion of the SQL code to interact with the database and access potentially valuable information. SQL injection is a common method of attack against adversaries. However, by taking appropriate precautions such as ensuring data encryption, protecting and testing web applications, and always staying informed about patches, there are meaningful steps toward keeping data secure. It is one of the most widespread and threatening types of attacks as it can be used against any web application or website that uses a SQL-based database.

Preventing SQL Injection Attacks

Training and Awareness

To maintain the security of a web application, everyone involved in its development should be aware of the risks associated with SQL injections. Adequate security training should be provided to all developers and quality assurance staff.

Do Not Trust Any User Inputs

Treat all user inputs as untrusted. Any user input used in an SQL query poses a risk of SQL injection. Handle inputs from authenticated or internal users in the same way as general input. Do not leave sensitive data in plain text; encrypt sensitive and confidential data stored in the database. This also provides an additional layer of protection in case an attacker succeeds in extracting sensitive data.

Use Whitelists, Not Blacklists

Avoid filtering user inputs based on blacklists, as clever attackers can find ways to bypass user-specific blacklists. If possible, verify and filter user input using strict whitelists only.

Adopt the Latest Technologies

Do not rely on outdated web development technologies susceptible to SQL injection. Use the latest version of the development environment and language, along with the most recent technologies associated with that environment and language. Keep databases updated with the latest available patches to prevent attackers from exploiting vulnerabilities and known flaws in older versions.

Employing Verified Mechanisms:

Avoid attempting to build SQL injection protection from scratch, as most modern development techniques can provide mechanisms to protect against SQL injection. Utilize such mechanisms instead of trying to reinvent the wheel. For example, use stored procedures in queries.

Avoid Using Dynamic SQL

This involves avoiding placing user-provided inputs directly into SQL statements and preferring prepared data and specific queries, which are more secure. Stored procedures are usually safer than dynamic SQL.

Sanitize User Input

Sanitizing user input means correctly escaping suspicious characters and verifying that the data type matches the expected type. Restricting database permissions and privileges, and setting database user capabilities to the minimum required, will limit what an attacker can do if they gain access. Additionally, avoid displaying database errors directly to the user, as attackers can use these error messages to gather information about the database.

Use a Web Application Firewall (WAF)

A WAF is a barrier that protects a web application, providing security against web-facing applications. It can help identify SQL injection attempts, and based on its configuration, it can also prevent SQL injection attempts from accessing the application and, consequently, the database. Employing a web application security testing solution to regularly test web applications interacting with databases can help discover new errors or vulnerabilities that may allow SQL injection.

Regularly Scan with Acunetix

SQL inputs may be introduced by developers or through libraries, modules, or external software. Users should regularly scan web applications for web vulnerabilities, such as Acunetix, a tool that automatically detects file injections.

Removing Potential Malicious Code Elements

It is a good idea to disable the display of database errors on production sites, as database errors can be used with SQL injection to gather information about the database. If a security vulnerability in SQL injection is detected, for example using a scan with Acunetix, it may not be possible to fix it immediately. For instance, the security hole might be in open-source code.

What are the Risks Associated with SQL Injection?

If this attack is successfully completed, SQL injection operations can be incredibly harmful to any company or individual. Once sensitive data is compromised in an attack, it may be challenging to fully recover. Databases are typically targeted for injection through applications such as a website that requests user input and then searches the database based on that input. However, direct targeting is also possible. SQL injection can pose various risks that may constitute serious threats to an organization, including:

• Deletion of Data or Tables: Malicious actors inject SQL to delete data or tables from the database. Even if there are backups, deleting data can impact the availability of the application until the database is restored. Furthermore, backups may not include recent data.

• Modification or Update of Data: Attackers use SQL injection to modify or update data in the database and add additional information. For example, in a financial application, an attacker could use SQL injection to alter account balances. Worse yet, attackers can gain administrative rights to the application's database.

• Data Theft: The most common risk of SQL injection is the theft of user data. Email addresses, login credentials, Personally Identifiable Information (PII), and other personal information can be stolen and sold on the dark web. Successful SQL injection poses a threat not only to the organization but also to its users.

Despite 20 years since the discovery of SQL injection, it remains a primary concern regarding data breaches and data security. In fact, recent attack trend analyses show a 47% increase in SQL injection attacks. "PII" is an abbreviation for "personally identifiable information."