How To Prevent SQL Injection


A recent report revealed SQL injection attacks are one of the most frequent vectors for breaking into organizational networks. For the period under analysis, SQL injection made up about 65% of all web application attacks.

A successful SQL injection attack can have far-reaching consequences for your organization. These attacks can result in lost or stolen confidential data, defaced websites, denial of services, and long-term compromised systems and networks.

The following blog discusses how to prevent SQL injection and how these attacks work.

What Is SQL?

SQL stands for Structured Query Language, which is a standard programming language designed for relational databases and is often used to share and manage data found in relational database management systems, including the data organized into tables.

SQL can be used to query, update, and reorganize data, create and modify the schema of database systems, and control access to its data. Although it is the oldest type of code, SQL is the most widely implemented database language to date.

What Is a SQL Injection Attack?

A SQL Injection Attack is a type of cyber attack that tricks an unsecured database to execute unauthorized and unsafe commands via the insertion of malicious code into the database's Structured Query Language (SQL). Although SQL injection (SQLi) has been around for a while, it still presents a formidable threat to most organizations today, and its vulnerability increases in organizations with poorly written APIs. So knowing how to prevent an SQL injection is still vital knowledge.

SQL injection actors leverage an entry field like a search bar, form fields, or login portal to execute an attack. Once they gain access to your systems, the hackers alter the entry data with a malicious snippet of code known as an exploit that tricks an unsecured database to interpret data as a command.

Notably, a dynamic SQL statement contains a predetermined set of parameters, such as a web form. The complete statement is only generated if a user fills in their inputs. Dynamic SQL statements with vulnerabilities allow attackers to enter complex scripts into forms to interfere with the preexisting parameters. This ultimately alters the meaning of the complete statement by changing, inserting, or deleting elements from a database, thereby laying the groundwork for a denial of service attack. Hackers can also leverage SQLi to install backdoors that give them access to a server indefinitely.

6 Ways to Prevent SQL Injection

If you're wondering how to prevent SQL injection, follow these 6 steps to ensure your business is safe.

1. Leverage Parameterized Queries (Prepared Statements)

You can prevent SQL injection attacks by cleaning up application codes via parameterized queries that distinguish between legitimate information and hacker information. Prepared statements ensure that an attacker cannot change the intent of a query, even if an attacker inserts SQL commands.

Properly input sanitation is undoubtedly a way to prevent SQL injection because its parameter values need not be correctly escaped. When the original SQL statement template is not derived from external input, SQL injection becomes a less attractive option for attackers.

2. Use a Web Application Firewall (WAF)

A web application firewall acts as a barrier to filter out malware and suspicious traffic between the internet and a web application. You can tweak your WAF to provide solid protection against all kinds of SQL injections and other forms of cyber-attacks such as cross-site scripting (XSS) and cookie poisoning, among others. If SQL injection vulnerability is in open source code, having a WAF might temporarily protect against new vulnerabilities while developing patches.

3. Database User With Restricted Privileges

You can substantially prevent SQL injection risks by limiting your application's privileges on your database. Practice the principle of least privilege, where database users will only have as much access as they need to do their duties.

Additionally, you can consider having multiple database users and connect them to specific application roles instead of having a single database user for your application. Security breaches typically involve a chain effect, and you should monitor every link in the chain to avoid heavy damage.

4. Regularly Update & Patch

Vulnerabilities in web applications and databases keep recurring. If left unaddressed, attackers can exploit these vulnerabilities using SQL injections. You need to update patches as soon as they are released for applications and databases.

5. Leverage an ORM layer

You can also use an object-relational mapping (ORM) layer to reduce the risks of SQLi attacks. An ORM layer helps transform the data from the database into objects and vice versa. Leveraging an ORM library can substantially reduce exposed SQL queries that increase the vulnerability to SQL injection.

6. Whitelist Rather Than Blacklisting

Although blacklisting prevents users from entering high-risk characters such as equal signs, semicolons, and quotation marks, savvy cybercriminals have found ways to get around blacklisting. Because whitelisting approves only specific characters, it is more restrictive, thus providing more excellent protection.

Real-Life SQL Injection Attack Examples

SQL injections happen in the real-world and have cost businesses plenty of time and money. Here are some SQL injection attack examples from high-profile companies.

Heartland Payment Systems attack: In 2008, hackers leveraged SQL injection to hack Heartland Payment Systems. The attackers stole 130 million credit card numbers.

Unique IDS and password combinations breach: In 2014, a Russian hacker group used SQL injection to steal over 1.2 billion unique IDS and password combinations from over 420,000 websites all across the internet.

Epic Games attack: A recent SQL injection attack example that garnered a lot of publicity is from 2016. Hacker groups attacked Epic Games forums, resulting in a data leak that affected 800000 user accounts.

Ghost shell attack: Hackers from SPT group team Ghostshell used SQL injection to attack 53 universities. The group stole and published 36000 personal records belonging to students, faculty, and staff.

Turkish government attack: RedHack collective group used SQL injection to breach the Turkish government website and erase debt to government agencies

Protect Against SQL Injection Attacks Today

Whether you are a website owner, an average internet user, or a big organization, you are vulnerable to SQL injection attacks. The widespread use of SQL guarantees that SQL injection will continue to be an imminent attack vector in the future.

As illustrated above, you have several options to prevent an attack. The best way to prevent SQL injection is to take adequate preventive measures. This way, organizations can safeguard their data and respond to threats early enough before the damage is done.

Stay up to date

Subscribe to the blog to stay up to date with all the latest industry news and updates from Electric.