Nextcloud server authorization issue vulnerability (CNVD-2022-20692)

Nextcloud is an open source self-hosted file synchronization and sharing communication application platform from Nextcloud Germany. nextcloud server is a self-hosted system designed to provide cloud-style services. nextcloud server is vulnerable to an authorization issue that stems from a lack of permission checking for specific subfiles. An attacker could exploit this vulnerability to gain unauthorized access to these subfolders by copying the group folder to another location.