sospiro@home:~$

InstantCMS 2.16.1 Cross Site Scripting

  • Exploit Title: InstantCMS - Store XSS
  • Application: InstantCMS
  • Version: v2.16.1
  • Bugs: Stored XSS
  • Technology: PHP
  • Vendor Homepage: https://instantcms.ru/
  • Software Link: https://instantcms.ru/get
  • Date: 14.09.2023
  • Author: SoSPiro
  • Tested on: Windows

Description

I noticed that you filtered the filter very carefully. But there are still some parts you missed

POC

  1. Login with admin
  2. Go to “http://localhost/o2/admin/menu/item_edit/18”
  3. Insert payload in CSS class
  4. Click save , and go to home page, and Detect store xss in footer

PoC-ViDeO

Impact

This security vulnerability has the potential to steal multiple users’ cookies, gain unauthorized access to that user’s account through stolen cookies, or redirect the user to other malicious websites…

Bug fix commit

Bug fix commit

Reference

Reference