What are SQL Injection Attacks?
How do SQL injection attacks affect a company’s work?
How to prevent them?
In today’s article, we are going to answer all your questions about SQL Injection Attacks. With the help of our developers and engineers, we have created this complete guide on SQL Injection Attacks.
So first of all let us talk about what is a SQL injection attack.
Table of Contents
What Are SQL Injection Attacks?
The term SQL stands for “Structured Query Language”. This language is created to manipulate and manage data in a database. It is mainly focused on a commercial and open-source database.
SQL Injection is a type of cybersecurity attack that targets these databases using specifically crafted SQL statements to trick the system into doing unexpected and undesirable things.
How SQL Injection Attack takes place?
- Bypassing authentication
- Exfiltrating/stealing data
- Modifying or corrupting data
- Deleting data
- Running arbitrary code
- Gaining root access to the system itself
How dangerous are SQL Injections?
SQL injections, if done correctly, have the potential to be extremely damaging to any company or individual. It might be difficult to entirely retrieve sensitive data once it has been compromised as a result of an assault.
Databases are often injected through an application (such as a website that seeks user input and then does a database query based on that information), but they can also be targeted directly.
Types of SQL Injection Attacks
SQL injection attacks are possible in a variety of ways. Attackers may monitor the behaviour of a system before deciding on an attack vector or tactic.
1. Unsanitized Input
Unsanitized input is a frequent SQL attack in which the attacker gives user input that hasn’t been properly sanitised for characters that should be escaped and/or haven’t been checked to be the correct/expected type.
For example, a website that allows users to pay bills online would ask for the user’s account number in a web form, which would then be sent to a database to get the account information. If the online application is dynamically creating a SQL query string using the account number given by the user, it may look like this:
“SELECT * FROM customers WHERE account = ‘” + userProvidedAccountNumber +”‘;” “SELECT * FROM customers WHERE account = ‘” + userProvidedAccountNumber +”‘;”
While this works for customers who input their account numbers correctly, it creates an open avenue for attackers. For example, if someone entered “‘ or ‘1’ Equals ‘1” as an account number, the query string would be:
“SELECT * FROM customers WHERE account =’or’1′ = ‘1’;”
Because ‘1’ = ‘1’ always evaluates to TRUE, submitting this statement to the database will return data for all customers rather than just one.
2. Blind SQL Injection
A Blind SQL injection attack, also known as Inferential SQL Injection, does not immediately divulge data from the targeted database. Instead, the assailant analyses behaviour for indirect signs. Depending on the SQL Injection attack mitigation purpose, details inside HTTP replies, blank web pages for particular user input, and how long it takes the database to reply to certain user input might all be indications. They might potentially direct the attacker to a different SQLi attack vector.
3. Out-of Band Injection
This is a more complicated assault that an attacker may employ if they can’t accomplish their aim with a single, simple query-response attack. Typically, an attacker will write SQL queries that, when provided to a database, will cause the database system to open a connection to an external server controlled by the attacker. In this way, the attacker might harvest data or manipulate the database’s behaviour.
A sort of Out-of-Band Injection attack is a Second Order Injection. In this situation, the attacker will send a SQL injection attack mitigation, which will be saved and performed by a database system behaviour. When the attacker’s SQL injection is executed and the secondary system activity occurs (it may be anything like a time-based task or something triggered by other usual admin or user database access), the “reach out” to a system the attacker controls occurs.
Examples Of SQL Injection Attacks
Let’s utilise two database tables for this SQL injection example: Users and Contacts. The Users table may only have three fields: ID, username, and password. More information about the users may be found in the Contacts database, which includes UserID, FirstName, LastName, Address1, Email, payment card number, and security code.
The Users database contains information that is used for logins, such as:
When storing passwords in a database, they should always be hashed and salted, never in plaintext.
To log in, go to the login page and enter your username and password. This data is then delivered to the website, which generates a SQL query and sends it to the database server. Here’s an example of what the query may look like:
Where username=’jsmith’ and password=’P@$$w0rd’, choose ID from Users.
The way SQL Injection Attack code works are that it does a true or false comparison for each record requested by the query. The query in our example checks the Users table and returns the ID value for each record with the username smith and the passworsmithw0rd. Often, the web server will check to see if the database server has returned a number. In our example, the webserver would get a 1 and allow the user to proceed through the login screen.
But what if we wish to use this to our advantage? We can fool the database server into thinking we’ve successfully authenticated since it uses a true-or-false check. By adding an OR to the password, we may do this. If we use the passwords xx’sor 1=1, we’ll get a new SQL query that looks like this:
Select ID from Users if the username is ‘smith and the password is ‘x’ or 1=1.
This will work for us since the database server will verify the second condition if x is not jsmith’s password. Does 1 equal 1 if x isn’t jsmith’s the password? Yes, it does! The ID will be returned to the programme, and the user will be authenticated successfully.
this doesn’t need to be a 1=1 condition. Any two equal numbers, such as 2=2, 4726=4726, or simply a=a, will work.
It may be feasible to print more data on the screen if a web page is capable of showing data. We can try to get the data by chaining two SQL injection attack codes together. We may add a second query like UNION SELECT LastName, credit card number, and security code from Contacts to our or 1=1 statement. Extra clauses like this may require additional effort, but the ultimate purpose of a SQL injection attack is to gain access to data.
Another method for blind SQL injection attack mitigation, in which no data is returned to the screen, is to insert additional hints. We may instruct the server to sleep in a similar way to our or 1=1 our Orion. We may add “‘or sleep(10) ” and it will appear to perform what we want. It will instruct the database server to take a 10-second sleep, delaying all answers.
Few Full-proof Tips to Prevent SQL Injection Attacks
The following tips can help you avoid a successful SQL injection attack:
1. Don’t rely on dynamic SQL.
Avoid explicitly inserting user-supplied data into SQL queries.
Prepared statements and parameterized queries are safer alternatives.
In most cases, stored procedures are safer than dynamic SQL.
2. User-provided inputs should be sanitised.
Escape the characters that need to be escaped properly.
Check that the data type given matches the data type anticipated.
3. Leave no critical information in plaintext.
Encrypt data in the database that is private or confidential.
The encrypted hashes should be salted.
This adds a layer of security in the event an attacker is successful in stealing critical information.
4. Permissions and privileges in the database should be limited.
Set the database user’s capabilities to the very minimum.
If an attacker manages to obtain access, they will be limited in what they can accomplish.
5. Avoid displaying database failures to the user directly.
These error messages might be used by attackers to get information about the database.
6. For web applications that access databases, use a Web Application Firewall (WAF).
Web-facing apps are protected as a result of this.
It can aid in the detection of SQL injection attack codes.
It may also assist in preventing SQL injection attempts from reaching the application, depending on the configuration (and, therefore, the database).
7. To test web programmes that interact with databases regularly, use a web application security testing solution.
This can aid in the detection of new flaws or regressions that could lead to SQL injection attack mitigation.
8. Keep your databases up to date with the most recent fixes.
This stops attackers from making use of known flaws or defects in previous versions.
SQL injection is a common attack tactic for attackers, but by taking the necessary measures, such as encrypting data, protecting and testing your online apps, and staying current with updates, you can take significant strides toward keeping your data safe.
Your online applications are increasingly at risk from criminal SQL injection attacks, especially if they access sensitive data. It is important to take precautionary steps to safeguard your systems against such attacks.
Apart from the tips we have mentioned, there are software and cybersecurity solutions that can protect your organization from SQL Injection Attacks and other cyber threats.
Contact WPG Consulting for expert solutions that take care of all your security concerns.