No, they don't have to MitM the CA's domain validation request. While they have brief control over the website, they use domain validation method 3.2.2.4.18 (A

No, they don't have to MitM the CA's domain validation request. While they have brief control over the website, they use domain validation method 3.2.2.4.18 (Agreed-Upon Change to Website v2)[1] or 3.2.2.4.19 (Agreed-Upon Change to Website - ACME)[2] to legitimately complete domain validation by making a change to the website. Due to domain validation reuse[3], the certificate doesn't have to be issued right away. The attacker can wait and request the certificate up to 398 days later, without having to do domain validation again. [1] https://github.com/cabforum/servercert/blob/cda0f92ee70121fd5d692685b97ebb6669c74fb7/docs/BR.md#322418-agreed-upon-change-to-website-v2 https://github.com/cabforum/servercert/blob/cda0f92ee70121fd... [2] https://github.com/cabforum/servercert/blob/cda0f92ee70121fd5d692685b97ebb6669c74fb7/docs/BR.md#322419-agreed-upon-change-to-website---acme https://github.com/cabforum/servercert/blob/cda0f92ee70121fd... [3] https://github.com/cabforum/servercert/blob/cda0f92ee70121fd5d692685b97ebb6669c74fb7/docs/BR.md#421-performing-identification-and-authentication-functions https://github.com/cabforum/servercert/blob/cda0f92ee70121fd...