What is SQL Injection? - ICSS

The hacker uses SQL injection to take advantage of the system's lack of data verification. In order to get access to sensitive data on the server, ordinary database queries are modified to suit the attacker. In the worst-case scenario, the attacker can modify databases and upload their own material. External and registered users can both utilise the access point for such injections.

First, the attacker must have a general understanding of the system. Every database is distinct in terms of structure and table names, such as for user information. Using standard frameworks, you can actively safeguard your system. They've been tried and true, and they're still evolving. Attacking such a framework gets even more difficult if it is further modified for your own system.

To figure out how queries are validated and which input types are utilised, the attacker must make many tries. Unfortunately, the error messages generated by these attempted injections may provide the attacker with the information they want to carry out their assault.

You may also use tests to uncover potentially hazardous vulnerabilities in the context of a full quality assurance procedure, and then eradicate them.

Tools For Detecting SQL Injection Vulnerabilities

Types Of SQL Injection

Error-based SQLi

Error-based SQLi is an in-band SQL injection method that uses the database server's error messages to gain information about the database's structure. An attacker may sometimes enumerate an entire database using just error-based SQL injection. While mistakes are important during the development phase of a web application, they should be deactivated on a live site or logged to a secure file.

Union-based SQLi

Union-based SQL injection uses the UNION SQL operator to aggregate the results of two or more SELECT queries into a single result, which is subsequently returned as part of the HTTP response.

Inferential SQLi(Blind SQLi)

Unlike in-band SQLi, inferential SQL Injection takes longer for an attacker to exploit, yet it is just as hazardous as any other type of SQL Injection. No data is actually sent over the web application in an inferential SQLi attack, and the attacker cannot see the result of an assault in-band (which is why such attacks are frequently referred to as "blind SQL Injection attacks"). Instead, by delivering payloads, watching the web application's response, and the database server's consequent activity, an attacker may rebuild the database structure.

Boolean-based (content-based) Blind SQLi

Boolean-based SQL Injection is an inferential SQL Injection method that uses a SQL query to cause the application to produce a different answer depending on whether the query returns TRUE or FALSE.The content of the HTTP response will vary or remain the same depending on the outcome.

Even though no data from the database is returned, an attacker can deduce if the payload used returned true or false. Because an attacker would have to enumerate a database character by character, this approach is generally slow (particularly on big databases).

Out-of-band SQLi

Out-of-band SQL injection is uncommon, owing to the fact that it relies on features being enabled on the database server that the web application uses. When an attacker is unable to launch and acquire data via the same channel, out-of-band SQL Injection happens.

Out-of-band approaches provide an attacker with an option to inferential time-based tactics, particularly if the server replies aren't always consistent (making an inferential time-based attack unreliable).

Out-of-band SQLi methods would rely on the database server's ability to provide data to an attacker via DNS or HTTP queries. Such is the case with the xp dirtree command in Microsoft SQL Server, which may be used to send DNS requests to a server controlled by an attacker, and the UTL_HTTP package in Oracle Database, which can be used to send HTTP requests from SQL and PL/SQL to a server controlled by an attacker.