LFI/RFI Security Awareness Guide

Understanding File Inclusion Vulnerabilities

File Inclusion vulnerabilities occur when applications improperly include files without proper validation. This guide explains the risks and defenses without providing executable exploit content.

Potential Impacts:

Sensitive data exposure
Application source code disclosure
System information leakage
Possible remote code execution

Vulnerability Patterns (Offensive)

1. Common Vulnerability Types

Basic Inclusion Patterns

// Example of vulnerable pattern (do not use)
$page = $_GET['page'];
include($page . '.php');

Dangerous PHP Functions

include(), include_once()
require(), require_once()
fopen(), file_get_contents()

2. Security Research Concepts

Path Traversal

Attempting to access files outside web root using ../ sequences

Wrapper Techniques

Using protocol wrappers to manipulate file handling (php://, data://)

3. Academic Resources

Reference Materials

MITRE CWE-98: PHP File Inclusion
OWASP Top 10 A05: Security Misconfiguration

Testing Methodologies

Static code analysis
Input validation testing
Controlled environment testing

Protection Strategies

1. Secure Coding Practices

Whitelist Approach

// Safe file inclusion example
$allowed = ['home', 'about', 'contact'];
if (in_array($_GET['page'], $allowed)) {
    include($_GET['page'] . '.php');
}

Basename Protection

$file = basename($_GET['file']);
include('/templates/' . $file);

2. Server Configuration

PHP Hardening

; php.ini security settings
allow_url_fopen = Off
allow_url_include = Off
open_basedir = /var/www/html/

Web Server Restrictions

Configure server to prevent access outside web root

3. Monitoring & Detection

Attack Indicators

Multiple ../ sequences in requests
Attempts to access known sensitive files
PHP wrapper usage attempts

Response Actions

Log and block suspicious requests
Review application logs
Update input validation rules

Educational Resources

Learning Materials

Defensive Guides

Security Best Practices

Never include files based on unvalidated user input
Use whitelists for allowed files/paths
Disable dangerous PHP functions and features
Configure open_basedir restrictions
Regularly audit file inclusion patterns
Implement proper file permissions

Legal Notice

This content is provided for educational purposes only to help secure applications. Never test vulnerabilities against systems without explicit permission. Unauthorized testing may violate laws and regulations.