Composr CMS 10.0.30 Cross Site Scripting

`# Title: Composr CMS 10.0.30 - Persistent Cross-Site Scripting  
# Author: Manuel Garcia Cardenas  
# Date: 2020-02-06  
# Vendor: https://compo.sr/  
# CVE: N/A  
  
  
=============================================  
MGC ALERT 2020-001  
- Original release date: February 06, 2020  
- Last revised: May 21, 2020  
- Discovered by: Manuel Garcia Cardenas  
- Severity: 4,8/10 (CVSS Base Score)  
- CVE-ID: CVE-2020-8789  
=============================================  
  
I. VULNERABILITY  
-------------------------  
Composr CMS 10.0.30 - (Authenticated) Cross-Site Scripting  
  
II. BACKGROUND  
-------------------------  
Composr CMS (or Composr) is a web application for creating websites. It is  
a combination of a Web content management system and Online community  
(Social Networking) software. Composr is licensed as free software and  
primarily written in the PHP programming language.  
  
III. DESCRIPTION  
-------------------------  
Has been detected a Persistent XSS vulnerability in Composr CMS, that  
allows the execution of arbitrary HTML/script code to be executed in the  
context of the victim user's browser.  
  
IV. PROOF OF CONCEPT  
-------------------------  
Go to: Security -> Usergroups -> Edit Usergroup  
  
Select one Usergroup (for example Guest) and edit the Name (parameter name)  
for example with Guests"><script>alert(1)</script>  
  
The variable "name" it is not sanitized, later, if some user visit the  
"Zone editor" area, the XSS is executed, in the response you can view:  
  
<input type="hidden" name="label_for__access_1" value="Access for  
Guests"><script>alert(1)</script>" />  
  
V. BUSINESS IMPACT  
-------------------------  
An attacker can execute arbitrary HTML or Javascript code in a targeted  
user's browser, this can leverage to steal sensitive information as user  
credentials, personal data, etc.  
  
VI. SYSTEMS AFFECTED  
-------------------------  
Composr CMS <= 10.0.30  
  
VII. SOLUTION  
-------------------------  
Disable until a fix is available.  
  
VIII. REFERENCES  
-------------------------  
https://compo.sr/  
  
IX. CREDITS  
-------------------------  
This vulnerability has been discovered and reported  
by Manuel Garcia Cardenas (advidsec (at) gmail (dot) com).  
  
X. REVISION HISTORY  
-------------------------  
February 06, 2020 1: Initial release  
May 21, 2020 2: Last revision  
  
XI. DISCLOSURE TIMELINE  
-------------------------  
February 06, 2020 1: Vulnerability acquired by Manuel Garcia Cardenas  
February 06, 2020 2: Send to vendor  
April 06, 2020 3: New request, vendor doesn't answer.  
May 21, 2020 4: Sent to lists  
  
XII. LEGAL NOTICES  
-------------------------  
The information contained within this advisory is supplied "as-is" with no  
warranties or guarantees of fitness of use or otherwise.  
  
XIII. ABOUT  
-------------------------  
Manuel Garcia Cardenas  
Pentester  
`