File Manager Advanced Shortcode <= 2.3.2 - Unauthenticated Remote Code Execution through shortcode

2023-05-3100:00:00

Mateus Machado Tesser

file manager advanced

unauthenticated user

remote code execution

shortcode

php file上传

security vulnerability

post parameter modification

file upload interception

9.8 High

CVSS3

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

7.5 High

CVSS2

Access Vector

NETWORK

Access Complexity

LOW

Authentication

NONE

Confidentiality Impact

PARTIAL

Integrity Impact

PARTIAL

Availability Impact

PARTIAL

AV:N/AC:L/Au:N/C:P/I:P/A:P

0.284 Low

EPSS

Percentile

96.9%

JSON

The plugin does not adequately prevent uploading files with disallowed MIME types when using the shortcode. This leads to RCE in cases where the allowed MIME type list does not include PHP files. In the worst case, this is available to unauthenticated users.

1. Add the following shortcode to a page:

[file_manager_advanced login="no" path="wp-content" hide="plugins" operations="upload,download" view="grid" theme="light" lang ="en" upload_allow="image/png" upload_max_size="2G"]

2. As an unauthenticated user, visit the page. Upload a PHP file and intercept the upload request.
3. Intercept the request and modify the POST parameter `upload_allow` to have the value `all`.
4. See that the PHP file was uploaded and can be accessed.