Document Title: =============== Simplephpscripts Simple CMS v2.1 - XSS Web Vulnerability References (Source): ==================== Release Date: ============= 2021-10-18 Vulnerability Laboratory ID (VL-ID): ==================================== 2301 Common Vulnerability Scoring System: ==================================== 5.1 Vulnerability Class: ==================== Cross Site Scripting - Non Persistent Current Estimated Price: ======================== 500€ - 1.000€ Product & Service Introduction: =============================== The system could be used only in already existing websites to control their page sections and contents. Just paste a single line of code on your web page section and start controlling it through the admin area. Very simple installation - one step installation wizard. Option to include contents into web page sections through php include, javascript or iframe embed. Any language support. WYSIWYG(text) editor to styling and format contents of the sections. Suitable for web designers who work with Mobirise, Xara and other web builders. (Copy of the Homepage: ) Abstract Advisory Information: ============================== The vulnerability laboratory core research team discovered a non-persistent cross site scripting vulnerability in the Simplephpscripts Simple CMS v2.1 web-application. Affected Product(s): ==================== Simplephpscripts Product: Simple CMS v2.1 - Content Management System (Web-Application) Vulnerability Disclosure Timeline: ================================== 2021-09-03: Researcher Notification & Coordination (Security Researcher) 2021-09-04: Vendor Notification (Security Department) 2021-10-01: Vendor Response/Feedback (Security Department) 2021-10-02: Vendor Fix/Patch (Service Developer Team) 2021-10-10: Security Acknowledgements (Security Department) 2021-11-18: Public Disclosure (Vulnerability Laboratory) Discovery Status: ================= Published Exploitation Technique: ======================= Remote Severity Level: =============== Medium Authentication Type: ==================== Pre Auth (No Privileges or Session) User Interaction: ================= Low User Interaction Disclosure Type: ================ Responsible Disclosure Technical Details & Description: ================================ A non-persistent cross site scripting vulnerability has been discovered in the official Simplephpscripts Simple CMS v2.1 web-application. The vulnerability allows remote attackers to inject own malicious script codes with non-persistent attack vector to compromise browser to web-application requests by the client-side. The cross site scripting vulnerability is located in the `id` parameter of the preview.php file. The request method to inject the malicious script code is GET and the attack vector of the vulnerability is non-persistent. The execution of the script code occurs in the undefined exception-handling output message. Successful exploitation of the vulnerability results in session hijacking, non-persistent phishing attacks, non-persistent external redirects to malicious source and non-persistent manipulation of affected application modules. Request Method(s): [+] GET Vulnerable Module(s): [+] Preview (Pages) Vulnerable File(s): [+] preview.php Vulnerable Parameter(s): [+] id Affected Module(s): [+] Undefined Exception-Handling (Preview) Proof of Concept (PoC): ======================= The non-persistent web vulnerability can be exploited by remote attackers without user account with low user interaction. For security demonstration or to reproduce the vulnerability follow the provided information and steps below to continue. PoC: Payload -1%3E%22%3Ciframe%20src=evil.source%20onload=alert(document.cookie)%3E PoC: Exploitation https://simple-cms.localhost:8000/simplecms/preview.php?id=-1%3E%22%3Ciframe%20src=evil.source%20onload=alert(document.cookie)%3E Vulnerable Source: preview.php (Exception-Handling) Simple CMS page -1>"<iframe src=evil.source onload=alert(document.cookie)> No page content with id -1>"