What is SQL Injection Attack (SQLI)?
SQL Injection is a backend database technique used by hackers to gain control of web applications by injecting malicious SQL code. SQLI attacks have become very popular because they are simple to execute and don’t require any technical knowledge. SQLI is a problem with web application servers that most developers don’t know about.
SQL Injection Types:
Hackers can insert malicious SQL codes by using a variety of methods, including retrieving data as errors, conditions, or time. Let’s take a closer look at SQL Injection types.
- Error Based SQL Injection
- SQL Injection Based On Boolean Errors
- SQL Injection can be done using Time Based Query
1. Error Based SQL Injection:
This allows hackers to easily retrieve information such as table names or content from database errors. Hackers could then identify the servers and make use of this information to attack production servers. This is why it is important to not display database error messages, which can be used to stop hackers from obtaining that information.
2. SQL Injection Based On Boolean Errors
Sometimes, the error message does not appear on the page where the SQL Query failed. This makes it more difficult for hackers to gain access to vulnerable applications. Hackers still have a way to access information. Sometimes, the entire website will crash or disappear when an SQL query fails.
These notifications are confirmed by the hacker who inserts a false condition in the SQL query to test for vulnerability and data extraction.
If the website loads normally after inserting this query, it will indicate that it is susceptible to an SQL injection. The hacker would then enter a wrong query to confirm the suspicion.
This condition is false, and if the website does not function as expected it indicates that the webpage is susceptible to SQL Injection attacks.
3. SQL Injection can be done using Time Based Query.
Vulnerable SQL queries can often be seen visually on a website, but it is still possible to find them. Hackers instruct the database to wait for a specified time before it responds. If they deny this and the site loads without any pause, likely, they aren’t vulnerable. This SQL query would look similar to a Boolean attack, but it would include a sleep function. If the sleep time is five seconds, it will instruct the database to go into sleep mode for five seconds.
Methods to Prevent SQL Queries:
False SQL queries can be avoided
These SQL queries can be difficult to find manually. There are also chances of getting lost. It is worth investing in website security software.
This issue can be validated by using web security software that checks every query. It hides vulnerable queries from the database so that web pages load properly even if they are found.
- Special characters like ( “”, “%”, “\”,”_, can be replaced with “_”,
- Database stores stored procedures
- Inquiries: Use prepaid statements