Injection is a web security risk that allows an attacker to tamper with database queries made by an application. It typically enables an attacker to gather and analyze data that they would not otherwise be able to get. This might include data belonging to other users or any other data that the application has access to. An attacker can often edit or delete this data, resulting in lasting changes to the application’s content or behaviour.

Why are SQL injections so dangerous and their impacts?

People think that a SQL injection is only really damaging when the attacker gets write privileges to the database, but that’s far from truth. A successful SQL injection attack can result in unauthorized access to sensitive data, such as passwords, credit card details, or personal user information. In some cases, an attacker can obtain a persistent backdoor into an organization’s systems, besides tarnishing your organization’s reputation, such a leak would cause consequences to your users/customers as the data is shared and sold. It could also put you in trouble with privacy regulations such as Europe’s GDPR or California’s CCPA, which could lead to severe legal and financial consequences.

Methods to prevent SQL injection

1. Verify user inputs

Verifying user inputs is a frequently used initial measure to minimize the chances of SQL injection. First, one must determine the most critical SQL statements and then create an allowlist for all acceptable SQL statements, leaving out any accounts that have not been validated. Data integrity, or query modification, is the term for this process.

Furthermore, one should configure user data entries as per the context. For instance, email address entry fields can be limited to only accept character inputs found in email addresses, including the compulsory “@” symbol. Social security numbers and telephone numbers should only be limited to enable the specific set of numbers for each. While this action will not protect from SQL injection hackers by itself, it will provide a layer of safeguards to the typical data-gathering methods used in SQL injection attacks.

2. Limit the use of special characters in data

Insufficient data cleaning is another factor to consider while defending against data breaches. Cleaning data to stop string compounding is crucial since SQL injection criminals can leverage unique character patterns to attack a database.

Configuring inputs to a program like MySQL’s real escape string () is one approach to accomplish this. This prevents any potentially harmful characters (for example, a single quote symbol) from being sent to a SQL statement as commands. Prepared statements are one of the most common ways to avoid unverified queries.

3. Enforce prepared statements and parameterizations

Unfortunately, input validation and information sanitization are not one-size-fits-all solutions. Businesses must employ prepared statements with parameterized queries for all SQL statements, sometimes called variable binding. You can differentiate between user intervention and code by declaring all SQL code associated with requests or parameterization.

Keep in mind that although flexible SQL as a coding style can provide more flexibility in app development, this can result in SQL injection vulnerabilities being accepted as valid code commands. This is because the server will consider harmful SQL queries as data rather than potential commands by using conventional SQL.

4. Make use of stored procedures in the database

Employing stored procedures necessitates variable binding in the same way that parameterization does. Stored procedures are saved in the database and invoked from the web app. However, remember that stored procedures may also be susceptible to security flaws if dynamic SQL creation is employed. According to organizations such as OWASP, one or the other parameterized ways is required, but neither strategy is sufficient for good security.

5. Actively manage patches and updates

SQL injection flaws in databases and programs are constantly discovered and disclosed publicly. As with many other concerns associated with cybersecurity, businesses must stay up-to-date on the news and implement upgrades and fixes quickly. This includes keeping all online application software aspects, such as database server programs, frameworks, libraries, connectors, and web server software up to date for SQL injection reasons.

See More: What Is a Security Vulnerability? Definition, Types, and Best Practices for Prevention

6. Implement a web application firewall

It is strongly advisable to use an appliance or software-based web application firewall (WAF) to filter out harmful material. Today’s firewalls, notably next-generation firewall (NGFW) and firewall as a service (FWaaS) options come with a robust set of specific provisions as well as the flexibility to adjust configurations as required. WAFs come in handy for SQL injection prevention when a patch or update is not yet available.

A prominent example is ModSecurity, a free, open-source component for Apache, Microsoft IIS, and Nginx web servers. ModSecurity has a complex and ever-changing set of rules for filtering potentially hazardous web requests. Its SQL injection safeguards detect many attempts to smuggle SQL across web channels.