CVE-2024-52522: Rclone has Improper Permission and Ownership Handling on Symlink Targets with --links and --metadata

Insecure handling of symlinks with --links and --metadata in rclone while copying to local disk allows unprivileged users to indirectly modify ownership and permissions on symlink target files when a superuser or privileged process performs a copy. This vulnerability could enable privilege escalation and unauthorized access to critical system files (e.g., /etc/shadow), compromising system integrity, confidentiality, and availability.

For instance, an unprivileged user could set a symlink to a sensitive file within their home directory, waiting for an administrator or automated process (e.g., a cron job running with elevated privileges) to copy their files with rclone using the –links and –metadata options. Upon copying, rclone will incorrectly apply chown and chmod to the symlink’s target file rather than just the symlink itself, resulting in ownership and permission changes on the sensitive file.