How SQL Injection Attacks in Kali Linux Work?
What is a SQL injection attack?
SQL injection is a common web application vulnerability. Attackers can bypass application verification and filtering through maliciously constructed SQL query strings, and then access or manipulate data in the database. This can lead to issues such as leaking sensitive information, compromising data integrity, and more.
Attack steps:
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Identifying targets: First, through application analysis, identify input points that may be vulnerable to SQL injection attacks, such as login forms, search boxes, etc.
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Constructing malicious input: Attackers construct malicious input by inserting special characters (such as single quotation marks) in the input box, with the purpose of changing how the application processes the input.
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Watch for error messages: If an application displays error messages on malicious input, attackers can use the error messages to learn about database structures and queries.
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Exploitation injection: Based on the observed error information, the attacker gradually constructs malicious queries to obtain sensitive data or perform inappropriate operations.
explain:
Suppose there is an imaginary web application with a login page. The attacker enters the following content in the username input box:
' OR '1'='1
In this way, the attacker constructs a malicious query such that the condition is always true. An application might use a query like the following to authenticate a user login:
SELECT * FROM users WHERE username = '' OR '1'='1' AND password = '输入的密码';
Since the condition of the malicious query is always true, an attacker may successfully bypass authentication and gain access to the application.
Case Study: Search Functionality for an E-Commerce Website
There is an e-commerce website where users can use the search function to find products. The search function retrieves related products by inserting the user's keywords into the SQL query. However, the developers did not fully consider security when building this feature.
- Search function code: The code for the search function is similar to the following example, where
$keywordis the search keyword entered by the user:
$query = "SELECT * FROM products WHERE name LIKE '%$keyword%'";
$result = mysqli_query($conn, $query);
- Attacker's Malicious Input: An attacker might enter the following in the search box:
' OR '1'='1
- Constructed query: At this point, the constructed query might resemble the following:
SELECT * FROM products WHERE name LIKE '%' OR '1'='1' %'
- Result: As a result, the database will return all products, as
'1'='1'always true.
In this way, an attacker can bypass the normal search logic and obtain data for all products and possibly other sensitive data.
explain:
This case is a common SQL injection attack scenario. The attacker successfully constructed a malicious SQL query by inserting special characters into the input box, bypassing the original search logic. Developers did not adequately filter and validate user input, leading to this security hole.
To protect against such attacks, developers should always adopt best practices such as using parameterized queries or prepared statements to process user input instead of directly concatenating input into SQL queries. Additionally, user input should be strictly validated and filtered to prevent malicious input.
Summarize:
Through the explanations, case studies, and possible code demonstrations in this article, I believe you have gained a deeper understanding of SQL injection attacks in Kali Linux. SQL injection is a serious security breach that can lead to serious consequences. As security practitioners, we need to be fully aware of this attack and take appropriate security measures to guard against it.
