Demi <= 0.0.8 - Unauthenticated Information Exposure to Arbitrary Directory Copy

Summary

The Demi – One Click Demo Import, WP Backup & Site Migration plugin for WordPress is vulnerable to Arbitrary Directory Copy in all versions up to, and including, 0.0.8 via the handle_restore_step function. This is due to missing HTTP access controls on the wp-content/uploads/demi-backup-state/ directory, which exposes the cryptographic restore key used to both authenticate the unauthenticated AJAX handler and forge signed restore-state envelopes. This makes it possible for unauthenticated attackers to copy arbitrary files to attacker-controlled destinations on the server. An active restore operation must have been initiated, which writes the .restore_key and .restore_step_token files to the public upload directory, before the exposed secrets can be harvested and chained to achieve unauthenticated arbitrary file copy.