One of the first things I learn about in cybersecurity was protecting against SQL injection attacks. These types of attacks started in the 1990s, and, to this date, some organizations still experience them. When using the internet, some websites require the user’s input, such as their username and password. Some users will provide the correct information, but some with ill motives will give an SQL statement.
So, what is an SQL injection attack? An SQL injection is an attack that can give an attacker complete control over your website’s database through malicious SQL statements. An attacker will use the vulnerabilities in your website or application to bypass security measures.
Once the attacker has control of your website or web application, they can retrieve the content of your entire SQL database. The attacker can also use the SQL injection to add, change or delete records in the database.
I’ve started to do some programming recently, so I can better learn about cybersecurity especially security within applications. I’m not an expert coder, it’s just a way for me to learn and I don’t necessarily need these coding skills to do my job. However, coding allows me to try out various SQL injection type attacks on the code I’ve created to give me a better understanding of the damage it can do, and the steps I can take to stop the SQL injection attacks in their tracks.
I can now see how devastating a SQL injection attack can be as it gives the opportunity to steal a lot of information, such as sensitive data like credit card numbers, social security numbers and other highly prized financial, medical and personal information. It makes a lot of sense to protect against these types of attacks especially in light of the damage these attacks can do.
I always advocate security being very important when developing a website, web applications or mobile application. If your website requires user information, you have the responsibility to protect such information from malicious individuals. Read on to find out more on how a SQL injection attack works and why an SQL injection attack is dangerous.
How Does a SQL Injection Attack Work?
Most people, especially those with businesses, create websites or mobile applications for their customers to find the product or service they are offering quickly. Most of these websites use SQL databases such as MySQL, Oracle, and SQL Server, most of which are prone to SQL injection attacks. Therefore, how does an SQL injection attack work?
An attacker will first find any vulnerability within the website or web application. The attacker will then create a malicious SQL statement, and the attacker will then send the SQL statement to the website, which will be executed in the database.
There are several types of SQL injection attacks, and an attacker will use the one suited to your website’s SQL vulnerabilities. An attacker will also need an SQL injection tool to carry out an attack, and most attackers keep using the old tools developed many years ago.
Without any vulnerabilities in your website’s SQL database, an attacker cannot gain access to your website or web application. SQL is a query language designed to manage the data stored in the databases. As the owner of the website, you can use SQL to access, modify and delete the data. If your database does not have enough security, an attacker will use their malicious SQL statement to access your database and do as they please.
There are several types of SQL injection attacks, and the simplest form of an SQL injection attack is through user input. Most websites will accept user input through a form, and the front end will pass the user input to the back-end database for processing. If the security on your website is poor, it will not check or sanitize the user input, and an attacker will use that weakness to inject any SQL statement into the back-end database.
Another type of SQL injection attack is the error-based SQL injection. Error-based SQL injection technique utilizes the error messages thrown by the database server to obtain information about the database’s structure. An attacker will learn how your website database is built and will create a malicious SQL statement to launch the attack. Once your website goes live, you should disable the errors or ensure they are logged to a file with restricted access only.
Inferential SQL injection or Blind SQL injection is where no data is transferred via the website, and the attacker cannot see the result of an attack. The attacker will reconstruct the database by sending payloads and observing your website’s response and the resultant behavior of the database server. There are two kinds of inferential SQL injection, one is Blind-Boolean-based SQL injection, and the other is Blind-time-based SQL injection.
A Boolean-based Blind SQL injection is where the attacker chooses to send an SQL query to your website’s database, forcing your website to respond with a different result depending on whether the query responds with a true or false result.
The content within your website’s response will either remain the same or change depending on the result received. The attacker would use the results to infer if their SQL query returned true or false even if no data was returned from the database.
An out-of-band SQL injection is not very common because it depends on features enabled on the database server being used by the website. Sometimes, an attacker cannot use the same channel to launch an attack; hence, they resort to an out-of-band SQL injection.
This technique offers the attacker an alternative to the inferential time-based techniques, especially if the server’s responses make inferential time-based attacks unreliable. The attacker relies on the database server’s ability to make DNS or HTTP requests to deliver data.
To carry out an SQL injection attack, an attacker needs to have an SQL injection tool. The most common tools used by attackers include SQLninja, SQLmap, and Havij. These SQL tools are for testing a website security system, but attackers can also use them to launch SQL injection attacks. You can use these tools to keep you a step ahead of any attackers. You can see any vulnerabilities in your SQL database and fix them before an attacker takes advantage of them.
Why Is SQL Injection Dangerous?
An SQL injection is one of the most common threats to a database system. If you own a website or web application, you need to know all the risks associated with an SQL injection attack and how you can deal with them.
Once an attacker launches an SQL injection attack, they can bypass your website’s authentication system. The attacker can gain control of your website or web application. Once the attacker controls the website, they can add, change, or delete records in the database and steal data.
The attacker can deny genuine users’ access to your website or web application. It is important to know how to detect an SQL injection attack. There are also ways you can use to prevent an SQL injection attack.
Authentication is very important when assigning database privileges after developing a website. The authorized user is responsible for the records in the database, and, if anything happens, it is easy to know whom to question.
Attackers use SQL injection attacks to bypass authentication and gain the privileges of an authorized user. If the attacker gains access to the database, they can cause both economic and emotional damage.
Most attackers using SQL injections want access to websites or web applications to change or delete certain records. When attackers gain access to a specific website, they can add, change, or delete some records. The attacker can also impersonate other users and gain sensitive or private information that they may use for criminal activities later.
Some attackers use SQL injection attacks as means to make easy money. The attacker will request that the website’s owner pay them a specific amount of money before relinquishing the database privileges back to the owners.
Sometimes, attackers use SQL injection attacks to cause disruption or halt a specific website from offering certain services. The attacker can flood the server with numerous useless requests, which will lock out genuine users from accessing the website.
If you are using your website to sell and promote your product or services, you will lose income until you regain control of the website. The attacker can also delete data regarding your business, which may be hard to recover if you do not have any backups.
An SQL injection attack can also affect the public image of your company. If you own a successful company, your customers expect you to have a good cybersecurity system to protect their private data. For example, if an SQL injection attack leads to the theft of thousands of credit card numbers belonging to your customers, it will be difficult to convince new customers to shop through your website. It might also cost you a lot of money to improve your company’s public image and improve the security system on your website.
How to Detect and Prevent an SQL Injection Attack
You cannot take a security threat against your website or web application lightly; therefore, you need to know how to detect a SQL injection attack.
A web application firewall (WAF) can help you detect and block some basic SQL injection attacks. You should also use an Intrusion Detection System (IDS) to detect SQL injection attacks. The IDS is divided into two, and you should use both the network-based IDS and the host-based IDS.
The network-based IDS shall monitor all connections in your database server and show you any suspicious activities. The host-based IDS will monitor the web server logs and show you if something out of the ordinary happens.
If you are the authorized user with access to the SQL server, you should be aware of the errors that appear on your computer when accessing the SQL server. Some of the errors can help you detect an SQL injection attack, such as, error 18456, which indicates failed logins when someone tries to use a wrong password to gain access.
Errors 102 and 105 indicate an ongoing SQL injection attack, but it has failed to execute because the syntax is incorrect. Errors 208 and 2812 show that the attacker tried to access an invalid object or procedure not available in your database. You should also be keen to watch all the errors that involve permissions to access the database.
There are steps you can take to prevent your websites from falling victim to any SQL injection attacks. The first step is to validate all user inputs. You need to identify all SQL statements and then establish a whitelist for all valid SQL statements and leave unvalidated SQL statements out of the query.
You can also configure inputs for user data according to context. Many people allow users to set up accounts and log in using their email addresses. Therefore, in the field where a user needs to input their email address, it can filter to only allow email address characters such as “@.”
Another useful step to preventing SQL attacks is to sanitize data by limiting special characters. SQL injection attackers usually use special character sequences to infiltrate a database. You can use MySQL’s mysql_real_real_real() to configure user inputs. You will prevent dangerous characters like a single quote from passing to a SQL query as instructions. You can also use prepared statements to sanitize unauthorized SQL statements.
Another important step to preventing SQL injection attacks is to manage patches and use updates. It is important to stay up to date with the most recent developments regarding SQL injections. Utilize patches and updates as soon as they are available to maintain the strength of your website security system. Do not miss any patch or updates; it might seem tiresome to always check for updates, but if you fail to install a patch or update, it could end up costing you a fortune to make this right.
You should also reduce your attack surface. An attack surface refers to the potential entry points that can be exploited by attackers if left open. You should get rid of any database functionalities that you do not need. If you do not need those functionalities, you might make the mistake of not guarding them anymore. An attacker may use the lapse in security to attack other database functionalities in your website.
Encryption is also another step in preventing SQL injection attacks. Encryption is the most common form of data protection. You can encrypt your passwords, confidential data, and connection strings, making it hard for attackers to use them. Even if the attacker gains access to your database, it will not be helpful to them if all the data is encrypted. Other steps for preventing SQL injection attacks may include limiting read access, denying access to extended URLs, and buying better software.
Using an Object Relationship Mapper (ORM) or using a library to parameterize SQL queries can provide a layer of protection against SQL injection attacks. As these methods, provide a layer to using raw SQL queries, so it becomes more difficult to inject SQL code that could have malicious actions.
I use Laravel for development learning and this includes a PHP Data Object (PDO) driver that accepts parameterized SQL queries, where the SQL parameter is bound to a specific column, making it difficult to access different columns or tables other than those specified in the PDO call.
Wrap-up
Most attackers try to find vulnerable spots in your web security system before launching an attack. There are several types of SQL injection attacks, and individuals will choose the one that will guarantee results. Once the attacker has access to your database, they can do whatever they want with the records. Some attackers use their opportunity to make money by demanding ransom before releasing the administrative privileges back to the owner.
When it comes to the early detection of SQL injection attacks, you need to treat all user inputs as malicious data. Blocking an attacker early before sending their malicious SQL statements is very important in protecting your website’s database.
You can use the suggestions in this article to detect and prevent SQL injection attacks. SQL injection attacks are straightforward to pull off, and it does not require the most intelligent person to carry it out. Therefore, you need to be constantly alert regarding preventing people from using SQL injection to attack your organization.
