Here's a quick
solutionFirst of all, test the files in a development/testing environment, not in production.
The zip contains a new file: "db_access.php". Put the same data you entered in "db_login.php" and that's it.
The reason for this quick fix is the problem of these vulnerabilities for access to the database via SQLInjection, so apply the solution as quickly as possible.
Using an SQLInjection attack the attacker can obtain the user data (including passwords) and would be prejudicial to users who use the same password on all sites (please NEVER do this)
Finally, if you find another security bug, don't be afraid to report it in the forum