Local File Inclusion (LFI) Vulnerabilities
Samark
Jul 03, 2024 - 15:32
What is LFI?
Local File Inclusion (LFI) is a type of security vulnerability found in web applications. It happens when an attacker tricks a website into displaying or running files from the server that it shouldn't have access to.
How Does LFI Work?
Imagine you have a website that allows you to view different pages by changing the URL. For example, you might see something like:
http://example.com/index.php?page=home
This URL tells the server to show the "home" page. However, if the website isn't properly secured, an attacker might change the URL to something like:
http://example.com/index.php?page=../../etc/passwd
Here, ../../etc/passwd is a path to a sensitive file on the server. If the server isn't checking the input properly, it might display the contents of this file, revealing sensitive information.
Why is LFI Dangerous?
1. Data Exposure: Attackers can view sensitive files, like configuration files or user data.
2. Code Execution: In some cases, attackers can run malicious code on the server.
3. Further Exploitation: LFI can be combined with other vulnerabilities to gain full control over the server.
How to Prevent LFI
1. Validate Inputs: Ensure that any input from users is checked and sanitized. Never trust user input blindly.
2. Use Whitelisting: Allow only specific, safe files to be included.
3. Server Configuration: Restrict access to sensitive files and directories.
4. Error Handling: Properly handle errors to avoid giving attackers clues about the file structure.
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