How do free website providers prevent fake payment pages being created on their (sub)domain?

Many providers of free websites allow the creation of subdomains.
What measures can these providers take to prevent (or mitigate) the following:

create a page demanding payment (with a link to an external payment gateway)
host it on a sub… Continue reading How do free website providers prevent fake payment pages being created on their (sub)domain?

Do subdomains of a TLD with mandatory HTTPS require a wildcard certificate?

Many new TLDs have mandatory HTTPS requirements. Is there a way to disable that for subdomains? If not does that mean an expensive wildcard SSL certificate will need to be used with these domains?
So if I have a service running at sub.doma… Continue reading Do subdomains of a TLD with mandatory HTTPS require a wildcard certificate?

Can strict ‘Referer’ validation also be bypassed with vulnerable subdomains?

I have been researching various common techniques for preventing CSRF attacks, such as SameSite, Secure, and CSRF Tokens, and how they can be bypassed. I found that the following vulnerabilities exist:

A website’s subdomain or sibling dom… Continue reading Can strict ‘Referer’ validation also be bypassed with vulnerable subdomains?

Are there any security reasons against "drop-www" (using example.com instead of www.example.com)?

Are there any security reasons against "drop-www"?
In other words, are there any security reasons against using an apex [1] domain name such as example.com instead of a subdomain such as www.example.com?
Quote https://www.bjornjo… Continue reading Are there any security reasons against "drop-www" (using example.com instead of www.example.com)?