What is SQL injection and how it can be prevented?

Cyber Security
#1

SQL Injection (SQLi) is a type of code injection attack where it manages to execute malicious SQL statements to control a database server behind a web application. Attackers mostly use this to avoid application security measures and thereby access, modify, and delete unauthorized data.

The following ways will help you to mitigate or prevent SQL injection attacks:

  • Include Prepared Statements (with Parameterized Queries)
  • Use Stored Procedures
  • Validate user input
  • Hide data from the error message
  • Update your system
  • Store database credentials separate and encrypted
  • Disable shell and any other functionalities you don’t need
1 Like
#2

An SQL injection attack is one easily understood instance of code injection,which is to say a place where code fails to treat inputs as potentially hostile and incorporates those inputs, directly or indirectly, into code to be executed.

SQL injection is almost never an attack on the DB per se. What it attacks is code which writes code which is then sent on to the DB. The code-generating code is often originally written by people who have vague and frequently wrong ideas of how to treat input as being potentially hostile, and is then used by people who know even less. This is not their fault. They weren’t taught, and they are frequently subjected to time pressures that make taking security into account impossible.

How to fix this:

  1. Under no circumstances should you be generating SQL code in an OLTP system. You can avoid doing this accidentally by not using ORMs.
  2. When you need to pass user input to the DB, do so via server-side prepared statements.
  3. If any of the terms in 1 and 2 are unfamiliar to you, get yourself very familiar with them before you write any code that interfaces with a DB.
#3

Structured Query Language or SQL is one of the most basic skills a budding computer programmer, or even a data analyst must master to boost their career track. Often considered as one of the simpler languages to begin with, it forms the base of queries that can be used to manipulate the databases, update, and bring out desired data from them by writing queries. Hackers, unfortunately, can use it to break into the databases to gather confidential data and jeopardize the operations.

SQLI or SQL Injection is an act used by hackers to get access into databases of the companies using simple but malicious query strings, compromising them to filter critical data and sometimes even erase or destroy them.

The act can be broadly classified into three segments:

In-Band SQLI:

Simple and yet efficient, this method is used to fill the databases with error messages, which are in turn used to gather deeper information about the database.

Inferential SQLI:

They rely solely on the behavioral patterns and responses from the database which are intercepted by sending data payload.

Out-of-band SQLI:

It happens when the hackers can’t use the same channel for their attack, and they can be carried about only when the databases have certain features enabled.

To defend their systems from these attacks, the IT Security department of the organizations must come up with proper plan to fail these attacks. The most popular ways can be presented as follows:

Better Coding Practices:

Writing codes that can identify any unauthorized and illegal attempts, this is a very complex process as it is always a tedious task to identify all the possible loopholes while writing codes and will leave room for vulnerability.

Use of proper Firewall setups:

Modern Firewall systems are used to prevent the entry and filter out illegal attempts of SQL injection. A “Web Application Firewall” of “WAF” keeps a record of possible malicious threats, which is used to tackle them

Protecting the data itself:

Perhaps the most proactive and most secure way of fighting these threats would be to have a data centric approach where the data in the databases itself is monitored and any suspicious behavior that fails to qualify the standard norms are reported and put to check.