: If no index file is found, and Directory Indexing is enabled in the server settings, the server generates a list of every file in that folder.
Leaving directory indexing enabled is often considered a "low-hanging fruit" for attackers. It leads to , where sensitive data not intended for public view is exposed: Why Is Directory Listing Dangerous? - Acunetix index of files link
: If indexing is disabled and no index file exists, the server blocks access. The Security Risk of Exposed Files : If no index file is found, and