What is the attack technique used to exploit websites by altering backend?
In this section, we'll explain what SQL injection (SQLi) is, describe some common examples, explain how to find and exploit various kinds of SQL injection vulnerabilities, and summarize how to prevent SQL injection. Show
What is SQL injection (SQLi)?SQL injection (SQLi) is a web security vulnerability that allows an attacker to interfere with the queries that an application makes to its database. It generally allows an attacker to view data that they are not normally able to retrieve. This might include data belonging to other users, or any other data that the application itself is able to access. In many cases, an attacker can modify or delete this data, causing persistent changes to the application's content or behavior. In some situations, an attacker can escalate an SQL injection attack to compromise the underlying server or other back-end infrastructure, or perform a denial-of-service attack. What is the impact of a successful SQL injection attack?A successful SQL injection attack can result in unauthorized access to sensitive data, such as passwords, credit card details, or personal user information. Many high-profile data breaches in recent years have been the result of SQL injection attacks, leading to reputational damage and regulatory fines. In some cases, an attacker can obtain a persistent backdoor into an organization's systems, leading to a long-term compromise that can go unnoticed for an extended period. SQL injection examplesThere are a wide variety of SQL injection vulnerabilities, attacks, and techniques, which arise in different situations. Some common SQL injection examples include: Retrieving hidden dataConsider a shopping application that displays products in different categories. When the user clicks on the Gifts category, their browser requests the URL: https://insecure-website.com/products?category=Gifts This causes the application to make an SQL query to retrieve details of the relevant products from the database: SELECT * FROM products WHERE category = 'Gifts' AND released = 1 This SQL query asks the database to return:
The restriction The application doesn't implement any defenses against SQL injection attacks, so an attacker can construct an attack like: https://insecure-website.com/products?category=Gifts'-- This results in the SQL query: SELECT * FROM products WHERE category = 'Gifts'--' AND released = 1 The key thing here is that the double-dash sequence Going further, an attacker can cause the application to display all the products in any category, including categories that they don't know about: https://insecure-website.com/products?category=Gifts'+OR+1=1-- This results in the SQL query: SELECT * FROM products WHERE category = 'Gifts' OR 1=1--' AND released = 1 The modified query will return all items where either the category is Gifts, or 1 is equal to 1. Since Consider an application that lets users log in with a username and password. If a user submits the username SELECT * FROM products WHERE category = 'Gifts' AND released = 1 3If the query returns the details of a user, then the login is successful. Otherwise, it is rejected. Here, an attacker can log in as any user without a password simply by using the SQL comment sequence SELECT * FROM products WHERE category = 'Gifts' AND released = 1 7This query returns the user whose username is Retrieving data from other database tablesIn cases where the results of an SQL query are returned within the application's responses, an attacker can leverage an SQL injection vulnerability to retrieve data from other tables within the database. This is done using the For example, if an application executes the following query containing the user input "Gifts": released = 1 1then an attacker can submit the input: released = 1 2This will cause the application to return all usernames and passwords along with the names and descriptions of products. Examining the databaseFollowing initial identification of an SQL injection vulnerability, it is generally useful to obtain some information about the database itself. This information can often pave the way for further exploitation. You can query the version details for the database. The way that this is done depends on the database type, so you can infer the database type from whichever technique works. For example, on Oracle you can execute: released = 1 3You can also determine what database tables exist, and which columns they contain. For example, on most databases you can execute the following query to list the tables: released = 1 4Blind SQL injection vulnerabilitiesMany instances of SQL injection are blind vulnerabilities. This means that the application does not return the results of the SQL query or the details of any database errors within its responses. Blind vulnerabilities can still be exploited to access unauthorized data, but the techniques involved are generally more complicated and difficult to perform. Depending on the nature of the vulnerability and the database involved, the following techniques can be used to exploit blind SQL injection vulnerabilities:
How to detect SQL injection vulnerabilitiesThe majority of SQL injection vulnerabilities can be found quickly and reliably using Burp Suite's web vulnerability scanner. SQL injection can be detected manually by using a systematic set of tests against every entry point in the application. This typically involves:
SQL injection in different parts of the queryMost SQL injection vulnerabilities arise within the But SQL injection vulnerabilities can in principle occur at any location within the query, and within different query types. The most common other locations where SQL injection arises are:
SQL injection in different contextsIn all of the labs so far, you've used the query string to inject your malicious SQL payload. However, it's important to note that you can perform SQL injection attacks using any controllable input that is processed as a SQL query by the application. For example, some websites take input in JSON or XML format and use this to query the database. These different formats may even provide alternative ways for you to that are otherwise blocked due to WAFs and other defense mechanisms. Weak implementations often just look for common SQL injection keywords within the request, so you may be able to bypass these filters by simply encoding or escaping characters in the prohibited keywords. For example, the following XML-based SQL injection uses an XML escape sequence to encode the released = 0 8This will be decoded server-side before being passed to the SQL interpreter. Second-order SQL injectionFirst-order SQL injection arises where the application takes user input from an HTTP request and, in the course of processing that request, incorporates the input into an SQL query in an unsafe way. In second-order SQL injection (also known as stored SQL injection), the application takes user input from an HTTP request and stores it for future use. This is usually done by placing the input into a database, but no vulnerability arises at the point where the data is stored. Later, when handling a different HTTP request, the application retrieves the stored data and incorporates it into an SQL query in an unsafe way. Second-order SQL injection often arises in situations where developers are aware of SQL injection vulnerabilities, and so safely handle the initial placement of the input into the database. When the data is later processed, it is deemed to be safe, since it was previously placed into the database safely. At this point, the data is handled in an unsafe way, because the developer wrongly deems it to be trusted. Database-specific factorsSome core features of the SQL language are implemented in the same way across popular database platforms, and so many ways of detecting and exploiting SQL injection vulnerabilities work identically on different types of database. However, there are also many differences between common databases. These mean that some techniques for detecting and exploiting SQL injection work differently on different platforms. For example:
How to prevent SQL injectionMost instances of SQL injection can be prevented by using parameterized queries (also known as prepared statements) instead of string concatenation within the query. The following code is vulnerable to SQL injection because the user input is concatenated directly into the query: released = 0 9This code can be easily rewritten in a way that prevents the user input from interfering with the query structure: https://insecure-website.com/products?category=Gifts'-- 0Parameterized queries can be used for any situation where untrusted input appears as data within the query, including the For a parameterized query to be effective in preventing SQL injection, the string that is used in the query must always be a hard-coded constant, and must never contain any variable data from any origin. Do not be tempted to decide case-by-case whether an item of data is trusted, and continue using string concatenation within the query for cases that are considered safe. It is all too easy to make mistakes about the possible origin of data, or for changes in other code to violate assumptions about what data is tainted. What is the attack technique used to exploit websites by altering backend database queries quiz?Expert-Verified Answer. "SQL injection attack techniques are used to damage the websites by changing the "backend database queries" by entering "manipulated queries". This is the "attack technique" that is used for exploiting the websites by changing SQL statements.
What is the attack technique used to exploit?SQL injection is an attack technique used to exploit code by altering back-end SQL statements through manipulating input.
What is used for attacking the web sites working with databases?SQL Injection (SQLi) is a type of an injection attack that makes it possible to execute malicious SQL statements. These statements control a database server behind a web application.
What type of cyber attack is SQL injection?SQL injection (SQLi) is a cyberattack that injects malicious SQL code into an application, allowing the attacker to view or modify a database. According to the Open Web Application Security Project, injection attacks, which include SQL injections, were the third most serious web application security risk in 2021.
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