Certificate issuance is the process a certificate authority uses to verify that the requester controls a domain before signing an HTTPS certificate. This check is essential because browsers trust the signed certificate as proof that a site is legitimate and able to encrypt traffic.
In attacks, certificate issuance can be abused when an attacker temporarily gains control of DNS or another validation channel and satisfies domain-control checks without owning the server. That can lead to a valid-looking certificate for a hostile endpoint, enabling phishing, man-in-the-middle setups, or trust confusion. Defenders reduce this risk by monitoring DNS changes, watching certificate transparency logs, and using strong validation and revocation processes.