C-MOR System Vulnerable to File Upload Attack via Backup Feature

Summary

An issue was discovered in za-internet C-MOR Video Surveillance 5.2401. Due to improper user input validation, it is possible to upload dangerous files, for instance PHP code, to the C-MOR system. By analyzing the C-MOR web interface, it was found out that the upload functionality for backup files allows an authenticated user to upload arbitrary files. The only condition is that the filename contains a .cbkf string. Therefore, webshell.cbkf.php is considered a valid file name for the C-MOR web application. Uploaded files are stored within the directory "/srv/www/backups" on the C-MOR system, and can thus be accessed via the URL https://<HOST>/backup/upload_<FILENAME>. Due to broken access control, low-privileged authenticated users can also use this file upload functionality.