What is a 400 HTTP request?

A 400 HTTP request indicates an error or bad request in the client's communication with the server.

Why do we send 400 requests to HTTPS ports?

According to experts, this practice is largely due to the widespread use of self-signed certificates and insecure connections over HTTP. By sending a 400 request, users can verify that their browser or software has detected an insecure connection.

How does it affect online security?

A 400 HTTP request sent to HTTPS ports can raise concerns about man-in-the-middle (MITM) attacks and data interception. If a user unknowingly connects to an unsecured port, their browser or software may not have the necessary protection against these threats.