Missing authentication for backup functionality in Kaon AR2140X

The Kaon AR2140X router contains a vulnerability where the backup functionality is accessible without authentication. This allows an unauthenticated remote attacker to trigger a configuration backup and retrieve it in a form encrypted by a device-specific key. Triggering this function renders the router inoperable for a substantial period of time.  This issue was identified in firmware versions up to 4.2.17. Status of newer versions remains unknown.