What is an SQL injection and how to prevent this attack?
SQL Injection remains one of the most prevalent attacks used by hackers and a serious security threat to both individuals and companies.
SQLi is also one of the most well-known web application vulnerabilities with a dedicated chapter in the OWASP Top 10 project and is also a highly chased vulnerability in bug bounty programs.
A common SQL injection attack happens when attackers try to insert malicious SQL statements located in an HTTP (or HTTPS) request by changing the current behavior of SQL statements created by the web application.
They do this by first finding a vulnerable user input within a web app and create input content which is often used as the malicious payload to launch this attack. The input provided by an attacker may include characters that could interfere with the SQL syntax and will result in arbitrary SQL queries performed on the database.
As a result, the risk of an SQL Injection vulnerability is that the attacker could:
- Read/write information from the database
- Read/write files from the disk (in certain conditions)
- Execute operating system commands on the database server (in certain conditions)
Here is a sample URL which extracts the type and version of the database server (MySQL) by exploiting the SQL Injection vulnerability:
http://vulnapp.example.com/travel.jsp?id=x' UNION SELECT NULL, NULL, @@version -- '
One of the most common types of SQL injection techniques is error-based SQL injection which is the simplest SQL exploit and easy to detect. It involves using classic HTTP requests by inserting unexpected commands through a user interface to cause the database server to respond with an error that includes information about the target: structure, version, or operating system.
In the below example, an SQL command has been inserted to change the value of the fields
Username ($username = 1' or '1' = '1) and
Password ($password = 1' or '1' = '1) which will be modified as follows:
Username (($username = 1' or '1' = '1') LIMIT 1/*)
Password ($password = foo)
This is an example of a URL with the modified query that will generate an error and let a hacker get access to all the user names and passwords.
http://www.example.com/index.php?username=1'%20or%20'1'%20=%20'1'))%20LIMIT%201/*&password=foo
To prevent this from happening, you should avoid using the user input directly in the application code. Developers need to sanitize the input section and remove the potentially malicious code in SQL statements that could allow hackers to gain unauthorized access to sensitive database information: usernames, passwords, and other essential credentials.
Prevention is always the best cure and you can simply detect web application vulnerabilities by using our online scanner.
How does the SQL Scanner work?
To better secure your web applications from SQL injection attack is to identify and fix security vulnerabilities before hackers do.
Our SQL injection scanner was created to easily perform SQL injection testing and find web applications flaws in a timely manner.
The SQL Injection Scanner using OWASP ZAP (Full Scan) is our comprehensive online security solution that allows you to do a complete SQL injection assessment of the target web applications and find critical vulnerabilities with a significant impact for any business.
The online tool offers an intuitive and simple interface using OWASP ZAP , the most popular open-source web application security scanner.
The SQL Injection Scanner (Light Scan) performs a quick and fast scan of a target URL that allows it to identify vulnerabilities in web applications. It does that by searching if the parameters of the target URLs are vulnerable to SQL Injection attack and reports the malicious pages that could affect your website.
The online scanner includes two steps:
- Spidering the target: In this first step, the scanner tries to identify all the pages within the target web application, including injectable parameters in login forms, URLs, headers, etc.
- Accurate SQL injection testing: During this phase, for each page discovered in the previous step, the online tool will try to detect if the parameters are vulnerable to SQL Injection and report them in the results page.
The table below shows the differences between the
Light scan and the
Full scan:
| Scanner capabilities |
Light scan |
Full scan |
| Spider max URLs |
20 |
500 |
| Spider max duration |
1 minute |
15 minutes |
| Active scan max duration |
2 minutes |
30 minutes |
Warning:
The SQL Injection tool generates some HTTP requests that can be flagged as attacks on the server side (although they are harmless). We recommend not to perform an SQL injection test if you don't have permission or proper authorization from the owner of the target web app.
Will this tool also check for MySQL Injection?
MySQL is one of the most accessible and widely deployed SQL databases running on websites and systems and also the top target for hackers. They will search for vulnerable user inputs within the MSQL databases, inject malicious code to manipulate them and get unauthorized access.
Our online tool will scan the target URL containing SQL commands and check if the MySQL database has been exposed to any SQL injection vulnerability. It can perform a full SQL injection assessment of the target web application to detect vulnerabilities before being compromised.
Other popular relational database management systems (RDBMS) that are vulnerable to SQL injection are Microsoft SQL Server, Oracle, or SQLite.
