Overview
When we talk about cyber threats, SQL injection attacks rank quite high in case of posing threats and dealing severe damage. SQL attacks, if successfully carried out, can result in the deletion of confidential data, defaced websites, unauthorised access to systems, and accounts, and compromising the entire system or even network. We will be talking about the types of SQL injection and attacks. In general, SQL is not a harmful medium. Data analysts and other data professionals use SQL. So, what is SQL, and why is it important? SQL is short for Structured Query Language, it is used for storing, retrieving, and harnessing data in the database. Presently, SQL is the most influential language a data professional must know to get hired.
Each day, a lot of data is generated, but they have no value when they are in raw form, hence data professionals use SQL to analyse and extract data for further use. You can say that SQL is the standard language for relational DBMS (Database Management System). MySQL, MS Access, Oracle, Sybase, Informix, Postgres, SQL Server etc. use SQL. Popular social media sites like Facebook, WhatsApp, etc. also use SQL for backend data storage.
When a query is run in SQL, it is run through a query optimizer. A query optimizer is a very important component in DBMS, it generates query plans for each query, and the most efficient query plan is then selected to run the query. Relevant information is retrieved from the database after the execution of the query.
Now, you must be thinking that if SQL is so helpful, how come it has a negative use? Well, it is a mere language, which means it is something neutral, the purpose of use totally depends on who is using the language.
SQL is so efficient that it has become an effective medium for attackers to launch cyberattacks of its nature.
What Does SQL Injection Look Like?
“An SQL injection attack involves the alternation of SQL statements that are used within a web application through the use of attacker-supplied data” As per Cisco. Various malicious attacks can be carried out based on the SQL statement designed by the attacker and the database plus application structure.
For example, a hacker injects their own SQL code into the SQL query (where a user enters their username and password) supposedly on Facebook, to log into its server/ website/DBMS without a password. After the intrusion, they can cause severe internal damage to the whole database of Facebook, or even unface the whole website beyond recovery.
Authentication Bypass
After infiltrating the core of the network or system, the hacker will gain administrative access, which means they will not need any login credentials to access the central system whenever they want.
Information Compromise
Hacker creates SQL injections to connect it to the database directly or indirectly to gain access to all the backend information. The hacker may use it to steal the data or launch even more severe attacks. In addition to snooping around in the database and core structure, the hacker can also alter the data.
In-Band SQL Attack
When the attacker gains the ability to launch an attack and gather information using the same channel through their SQL attack, it’s called an in-band SQL injection attack. Out of all the types, this type of attack is the most common.
Error-Based SQL
This is a type of in-band SQL injection attack, it is launched when the database server displays an error message to obtain information or access the backend database. A strong error-based SQL injection is enough to list out the data in the database one by one separately.
To avoid such attacks, it is necessary to eliminate all the error messages generated during the progress stage of an app or software, while it goes live.
Union SQL Injection
Hackers use union operators in their SQL statement. The union operator then takes several queries and combines the results in one set for all the queries under the union. The result is then sent to the hacker in the form of a URL for direct access to the database.
Inferential SQL Injection
SQL attacks of this nature do not yield a direct result, the hacker doesn’t get any data in return after the implementation of inferential SQLi. Though this attack is slow and indirect, it is as dangerous as other SQL attacks.
The attacker can restructure a database by sending payloads (the result sent through HTTP after the GET request is generated) and observing the response and resulting behaviour of the website or database to this action.
Out OF Band SQL injection
When the attacker doesn’t have the option to launch an SQL attack and gather information through the same channel, they use an out-of-band attack. It is mostly used when the server is not as stable and the success rate of inferential attack is low.
Strategies To Prevent SQL Attacks
Since SQL is a dynamic attack, many solutions have been designed specifically to pacify these attacks. One such solution is the WAF (Web Application Firewall), which can detect SQL related activities and stop them from happening.
IDS (Intrusion Detection System) deployment can be used to monitor the database server as well as web server log connections on both network-level and host-based systems, it sends reports of any suspicious activity taking place.
Cybersecurity professionals need to have an in-depth knowledge of SQL attacks and their variations. As the internet is evolving, so are the nature and strength of cyberattacks. Cybercriminals always search for new ways to penetrate through the latest security technologies and software, hence it is very important to take the help of cybersecurity companies to keep your system safe. A good cybersecurity service provider helps you secure your network, website, and systems on various levels so that you can work tension free.
