Elefant CMS 1.3.12-RC: Multiple Persistent and Reflected XSS

Date: 2017-02-02 13:43:04

1. Introduction

2. Overview

Elefant is a content managment system written in PHP. In version 1.3.12-RC, it is vulnerable to multiple persistent as well as a reflected XSS issue. To exploit these vulnerabilities a user account is required most of the time but registration is open by default. XSS allows an attacker to steal cookies, inject JavaScript keyloggers, or bypass CSRF protection.

3. Details

Persistent XSS: Username

CVSS: Medium 5.0 AV:N/AC:L/Au:N/C:N/I:P/A:N

The username is echoed in various locations in the administration backend without encoding, leading to persistent XSS vulnerabilities. A user account is required, but the registration is open by default.

Proof of Concept:

1. Register a new user (the registration is open by default). 2. Update the profile, as name use: Username<img src=no onerror=alert(1)> To trigger the payload: 1. Log in as admin 2. View the edit page for the user, for example: http://localhost/user/edit?id=3 Alternatively, the payload is also echoed on the page listing all users: http://localhost/admin/versions?id=&type=User As well as on the version page: http://localhost/admin/versions?type=User&id=3

Persistent XSS: Version Comparison

CVSS: Medium 5.0 AV:N/AC:L/Au:N/C:N/I:P/A:N

Various fields of various components are echoed unencoded when comparing versions of those components. Examples are the user profile fields Name, Address, Address 2, City, Title, Company, or About, or the Title, Menu Title, Window Title, Description, or Keyword of a page.

Proof of Concept:

The comparison page can for example be seen here: http://localhost/admin/compare?id=8¤t=no

Persistent XSS: Page & Content Block

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

The title of a new webpage is echoed unencoded, leading to persistent XSS. The same issue also exists when creating blocks.

A user account with the right to create pages is required. By default, the editor role has this right.

Proof of Concept:

Create a new page or block, as title use: </title><img src=no onerror=alert(1)> The payload will be echoed in a title tag as well as a h1 tag when viewing the page and when editing the page.

Persistent XSS: Blog Post

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

The title as well as the tags of a blog post are echoed unencoded, leading to persistent XSS.

A user account with the right to create pages is required. By default, the editor role has this right

Proof of Concept:

Create a new blog post, as title and tag use: </title>'"><img src=no onerror=alert(1)> The payload will be echoed in a title tag, a h1 tag, as well as a href tag when viewing the page and when editing the page.

Reflected XSS

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

The name parameter of the custom fields component is vulnerable to reflected XSS.

Proof of Concept:

GET /admin/extended?extends=User&name=%3Cimg%20src=no%20onerror=alert(1)%3E HTTP/1.1

4. Solution

To mitigate this issue please upgrade at least to version 1.3.13.

Please note that a newer version might already be available.

5. Report Timeline