Security Advisory - Curesec Research Team

1. Introduction

Affected Product:    PivotX 2.3.11
Fixed in:            not fixed
Fixed Version Link:  n/a
Vendor Website:      http://pivotx.net/
Vulnerability Type:  Code Execution
Remote Exploitable:  Yes
Reported to vendor:  01/20/2016
Disclosed to public: 03/15/2016
Release mode:        Full Disclosure
CVE:                 n/a
Credits              Tim Coen of Curesec GmbH

2. Overview

PivotX is a CMS for blogging written in PHP. In version 2.3.11, it is
vulnerable to code execution by authenticated users because it does not check
the extension of files when renaming them.

3. Details

Description

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

The file upload functionality checks file extensions when uploading files to
prevent the uploading of malicious files such as PHP files. However, the rename
function does not check the extension of the new filename, leading to code
execution.

An account in the advanced users, admins, or superadmins role is required to
upload files.

Proof of Concept

1. Upload an image file containing PHP code with a valid extension such as png
2. rename it so it has a PHP extension: http://localhost/pivotx_latest/pivotx/
index.php?page=media&file=imageshell.png&pivotxsession=ovyyn4ob2jc5ym92&answer=
shell.php

4. Solution

This issue was not fixed by the vendor.

5. Report Timeline

01/20/2016 Informed Vendor about Issue
01/29/2016 Vendor replies, PivotX is not maintained anymore
03/15/2016 Disclosed to public


Blog Reference:
https://blog.curesec.com/article/blog/PivotX-2311-Code-Execution-153.html
 
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Curesec GmbH
Curesec Research Team
Romain-Rolland-Str 14-24
13089 Berlin, Germany