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Vol. 1 · Ed. 2026
CyberGlossary
Entry № 155

CAA Record (Certification Authority Authorization)

O que é CAA Record (Certification Authority Authorization)?

CAA Record (Certification Authority Authorization)A DNS record type (RFC 8659) that lets a domain owner restrict which Certificate Authorities are allowed to issue certificates for the domain, blocking accidental or malicious mis-issuance by other CAs.


A CAA record (Certification Authority Authorization, originally RFC 6844 and updated by RFC 8659) is a DNS resource record that lets a domain owner enumerate exactly which CAs may issue certificates for the domain. The record carries three fields: a flag byte, a property tag (`issue`, `issuewild`, `iodef`), and a value (typically a CA's issuer name such as `letsencrypt.org` or `digicert.com`). Since September 2017, all CAB Forum-trusted public CAs are required by the Baseline Requirements to check CAA records before issuing certificates and to refuse issuance if the record forbids them. A typical hardened deployment looks like `example.com. CAA 0 issue "letsencrypt.org"; example.com. CAA 0 issuewild ";"; example.com. CAA 0 iodef "mailto:security@example.com"`. The third record asks misbehaving CAs to report any rejected issuance attempt. CAA significantly reduces the risk of cert mis-issuance — by typosquatted domains, by hijacked CA accounts, by lookalike-CAs in obscure trust stores — and is one of the simplest single-record web-hygiene wins available. It pairs naturally with Certificate Transparency monitoring.

Exemplos

  1. 01

    An organization publishes `CAA 0 issue "letsencrypt.org"` so that no other public CA can issue end-entity certificates for the domain.

  2. 02

    A CT-monitoring alert fires on a certificate issued for the domain by a CA not listed in its CAA records, indicating either a misconfiguration or a CA non-compliance event.

Perguntas frequentes

O que é CAA Record (Certification Authority Authorization)?

A DNS record type (RFC 8659) that lets a domain owner restrict which Certificate Authorities are allowed to issue certificates for the domain, blocking accidental or malicious mis-issuance by other CAs. Pertence à categoria Segurança de rede da cibersegurança.

O que significa CAA Record (Certification Authority Authorization)?

A DNS record type (RFC 8659) that lets a domain owner restrict which Certificate Authorities are allowed to issue certificates for the domain, blocking accidental or malicious mis-issuance by other CAs.

Como funciona CAA Record (Certification Authority Authorization)?

A CAA record (Certification Authority Authorization, originally RFC 6844 and updated by RFC 8659) is a DNS resource record that lets a domain owner enumerate exactly which CAs may issue certificates for the domain. The record carries three fields: a flag byte, a property tag (`issue`, `issuewild`, `iodef`), and a value (typically a CA's issuer name such as `letsencrypt.org` or `digicert.com`). Since September 2017, all CAB Forum-trusted public CAs are required by the Baseline Requirements to check CAA records before issuing certificates and to refuse issuance if the record forbids them. A typical hardened deployment looks like `example.com. CAA 0 issue "letsencrypt.org"; example.com. CAA 0 issuewild ";"; example.com. CAA 0 iodef "mailto:security@example.com"`. The third record asks misbehaving CAs to report any rejected issuance attempt. CAA significantly reduces the risk of cert mis-issuance — by typosquatted domains, by hijacked CA accounts, by lookalike-CAs in obscure trust stores — and is one of the simplest single-record web-hygiene wins available. It pairs naturally with Certificate Transparency monitoring.

Como se defender contra CAA Record (Certification Authority Authorization)?

As defesas contra CAA Record (Certification Authority Authorization) costumam combinar controles técnicos e práticas operacionais, conforme detalhado na definição acima.

Quais são outros nomes para CAA Record (Certification Authority Authorization)?

Nomes alternativos comuns: Certification Authority Authorization, CAA DNS record.

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