danpros HTMLy Admin Content Endpoint admin.php add_content path traversal

A security flaw has been discovered in danpros HTMLy up to 3.1.1. This affects the function add_content of the file /system/admin/admin.php of the component Admin Content Endpoint. Performing a manipulation of the argument oldfile results in path traversal. The attack may be initiated remotely. The exploit has been released to the public and may be used for attacks. The vendor was contacted early about this disclosure but did not respond in any way.