SQL Injection

Everything you need to know about SQL Injection💉🌐

A SQL injection is a type of cyberattack that occurs when an attacker injects malicious 'Structured Query Language' code into a vulnerable SQL database-driven application.

This injection typically exploits security vulnerabilities in the application's input validation mechanisms, allowing the attacker to manipulate the SQL queries executed by the application.

The consequences of a successful SQL injection attack can be severe and include unauthorised access to sensitive data, manipulation or deletion of data, execution of arbitrary commands on the database server and even complete compromise of the underlying server or network.

SQL injection attacks can be classified into several types, including:

1️. In-band SQL injection: The attacker uses the same communication channel to both launch the attack and retrieve the results.

This can be further divided into:  

➡️Error-based SQL injection: The attacker exploits error messages returned by the database server to gather information about the database structure or to execute additional queries.  

➡️Union-based SQL injection: The attacker uses the UNION SQL operator to combine the results of multiple SELECT queries into a single result set.

2️. Out-of-band SQL injection: The attacker uses a separate channel to launch the attack and retrieve the results.

This may involve techniques such as DNS requests or HTTP requests to communicate with the attacker-controlled server.

3️. Blind SQL injection: The attacker does not receive direct feedback from the application about the success or failure of the injected SQL queries.

This type of injection is typically slower and requires more effort from the attacker, but it can still be exploited to extract sensitive information.

SQL injection attacks are preventable through various measures, including input validation and parameterised queries, which help sanitise user input and prevent malicious SQL code from being executed.

Implementing least privilege access controls, regularly patching and updating software and conducting security audits can help mitigate the risk of SQL injection vulnerabilities.