Kajona 4.7 - Cross-Site Scripting / Directory Traversal

🗓️ 19 Sep 2016 00:00:00Reported by Curesec Research TeamType
Kajona 4.7 open source CMS PHP vulnerability to XSS & Directory Traversa
Security Advisory - Curesec Research Team

1. Introduction

Affected Product:    Kajona 4.7
Fixed in:            5.0
Fixed Version Link:  https://www.kajona.de/en/Downloads/downloads.get_kajona.html
Vendor Website:      https://www.kajona.de/
Vulnerability Type:  XSS & Directory Traversal
Remote Exploitable:  Yes
Reported to vendor:  04/11/2016
Disclosed to public: 09/15/2016
Release mode:        Coordinated Release
CVE:                 n/a
Credits              Tim Coen of Curesec GmbH

2. Overview

Kajona is an open source CMS written in PHP. In version 4.7, it is vulnerable
to multiple XSS attacks and limited directory traversal.

The XSS vulnerabilities are reflected as well as persistent, and can lead to
the stealing of cookies, injection of keyloggers, or the bypassing of CSRF
protection.

The directory traversal issue gives information about which files exist on a
system, and thus allows an attacker to gather information about a system.

3. Details

XSS 1: Reflected XSS

CVSS: Medium 4.3 AV:N/AC:M/Au:N/C:N/I:P/A:N

The function that parses admin requests echoes user input into a JavaScript
context without escaping, leading to reflected XSS. As the injection takes
place into a JavaScript context, browser filters will generally not be able to
filter out an attack.

In the case of Kajona, XSS may lead to code execution, as admins can upload PHP
files via the media manager.

Proof of Concept:


http://localhost/kajona/index.php?admin=1&module=search&action=search&peClose=1&peRefreshPage=';alert(1);foo='

Code:


core/module_system/system/class_request_dispatcher.php
$strReturn = "<html><head></head><body onload=\"parent.location = '" . urldecode(getGet("peRefreshPage")) . "';\"></body></html>";

XSS 2: Reflected XSS

CVSS: Medium 4.3 AV:N/AC:M/Au:N/C:N/I:P/A:N

The media manager echoes the form_element parameter into a JavaScript context
without escaping, leading to reflected XSS. As the injection takes place into a
JavaScript context, browser filters will generally not be able to filter out an
attack. Note that a valid systemid id is required.

Proof of Concept:


http://localhost/kajona/index.php?admin=1&module=mediamanager&action=folderContentFolderviewMode&systemid=[VALID_SYSTEM_ID]&form_element=']]);alert(1);KAJONA.admin.folderview.selectCallback([['#

 Click on "Accept" overlay of an image to trigger the injected code.

XSS 3: Reflected XSS

CVSS: Medium 4.3 AV:N/AC:M/Au:N/C:N/I:P/A:N

The "class_messageprovider_exceptions_enabled" parameter of the xml.php script
is vulnerable to reflected XSS.

Proof of Concept:


http://localhost/kajona/xml.php?admin=1&module=messaging&action=saveConfigAjax&systemid=&class_messageprovider_exceptions_enabled=false<a xmlns%3aa%3d'http%3a%2f%2fwww.w3.org%2f1999%2fxhtml'><a%3abody onload%3d'alert(1)'%2f><%2fa>&messageprovidertype=class_messageprovider_exceptions

XSS 4: Persistent XSS

CVSS: Medium 4.3 AV:N/AC:M/Au:N/C:N/I:P/A:N

When creating a comment, the subject is vulnerable to persistent XSS. The click
of an admin is required to execute the injected JavaScript code.

Proof of Concept:


1. Leave a comment:
    http://localhost/kajona/index.php?page=postacomment

2. As subject, use:
    ');alert('1

3. Visit the comment overview:
    http://localhost/kajona/index.php?admin=1&module=postacomment&action=list

4. Click edit on the comment

5. Click on "Edit Tags" (the second symbol from the right)

Directory Traversal

When viewing images, the file name is improperly sanitized, allowing for
directory traversal.

It is not possible to actually read out files, as there are additional checks
in place preventing that. But an unauthenticated attacker can still see which
files exist on a system and which do not, making it possible to collect
information for further attacks.

Proof of Concept:


GET /kajona/image.php?image=/files/images/upload/....//....//....//download.php&maxWidth=20&maxHeight=2 HTTP/1.1
-> 200 (but not shown)

GET /kajona/image.php?image=/files/images/upload/....//....//....//foobar.php&maxWidth=20&maxHeight=2 HTTP/1.1
-> 404

Code:


core/module_system/image.php
    public function __construct() {
//find the params to use
$this->strFilename = urldecode(getGet("image"));
//avoid directory traversing
$this->strFilename = str_replace("../", "", $this->strFilename);
[...]
    }

    [...]

    private function resizeImage() {
//Load the image-dimensions
if(is_file(_realpath_ . $this->strFilename) && (uniStrpos($this->strFilename, "/files") !== false || uniStrpos($this->strFilename, "/templates") !== false)) {

    [...]
}


class_response_object::getInstance()->setStrStatusCode(class_http_statuscodes::SC_NOT_FOUND);
class_response_object::getInstance()->sendHeaders();
    }

4. Solution

To mitigate this issue please upgrade at least to version 5.0:

https://www.kajona.de/en/Downloads/downloads.get_kajona.html

Please note that a newer version might already be available.

5. Report Timeline

04/11/2016 Informed Vendor about Issue
04/13/2016 Vendor applies fix to github
05/25/2016 Vendor releases fixed version
09/15/2016 Disclosed to public


Blog Reference:
https://www.curesec.com/blog/article/blog/Kajona-47-XSS-amp-Directory-Traversal-163.html
 
--
blog:  https://www.curesec.com/blog
tweet: https://twitter.com/curesec

Curesec GmbH
Curesec Research Team
Josef-Orlopp-StraAe 54
10365 Berlin, Germany
19 Sep 2016 00:00Current
7.4High risk
Vulners AI Score7.4