Who Can Issue SSL Certificates for Your Site? The Importance of CAA Records

That little lock icon in your browser's address bar is a symbol of trust. It tells you that your connection to a website is encrypted with SSL and is secure.

But have you ever considered this question: What if someone could trick a Certificate Authority (CA) into issuing a "fake" but valid SSL certificate for your domain that they control?

This isn't a hypothetical threat; it has happened in the past. To prevent this, a DNS record called CAA (Certificate Authority Authorization) was created.

What is CAA and Why is It So Important?

A CAA record acts as a "whitelist of authorized Certificate Authorities" for your domain.

Through a simple DNS record, it makes a public declaration: "Only the specific companies I list (e.g., Let's Encrypt, Google Trust Services) are permitted to issue SSL certificates for my domain."

By industry mandate, all reputable Certificate Authorities must check a domain's CAA record before issuing a certificate. If they find that they are not on this "whitelist," they are required to refuse the issuance.

The dangers of not having a CAA record:

• Certificate Mis-issuance: An attacker could exploit a vulnerability in a less-reputable CA to obtain a valid SSL certificate for your domain.
• Risk of Man-in-the-Middle (MITM) Attacks: Armed with a valid certificate for your domain, an attacker could intercept traffic between your users and your site, stealing sensitive information without triggering any browser warnings.
• Loss of Control: You are effectively ceding control, allowing any of the hundreds of CAs worldwide to vouch for your brand, which introduces unnecessary risk.

How to Fix It: Adding CAA Records

The fix is straightforward and involves adding a few CAA records in your DNS provider's dashboard.

Step 1: Identify Your Current Certificate Authority (CA)

Visit your website in a browser, click the lock icon, and view the certificate details to find the "Issuer." Common issuers include Let's Encrypt or Google Trust Services.

Step 2: Add Three CAA Records

Let's assume your CA is Let's Encrypt (whose domain identifier is letsencrypt.org).

1. Authorize non-wildcard certificates (issue):
   • Type: CAA, Name: @, Tag: issue, Value: letsencrypt.org
2. Authorize wildcard certificates (issuewild):
   • Type: CAA, Name: @, Tag: issuewild, Value: letsencrypt.org
3. Set up violation reporting (iodef):
   • Type: CAA, Name: @, Tag: iodef, Value: mailto:[email protected]

Tip: On platforms like Cloudflare, the issue tag may be labeled "Only allow specific hostnames," issuewild as "Only allow wildcards," and iodef as "Send violation reports."

How to Verify the Fix

After adding the records, you can use the SSL Labs Test (ssllabs.com/ssltest/) for a comprehensive check.

In the test report's "Configuration" section, look for "Certificate Authority Authorization (CAA)." If it says "Yes" and lists the rules you set, the configuration is successful.

Security Should Be a Platform's Standard Feature

CAA, DMARC, SPF, HSTS... the list of security acronyms needed to maintain a modern website keeps growing. For a creator focused on content, this is a distraction and a burden.

At Postion, we see security as a fundamental responsibility of the platform, not an extra task for the user. Every site created on Postion is automatically configured with strict CAA records and DMARC policies. We handle this complex, back-end work so you can have 100% confidence that your brand and your users are protected.

Want a platform that's as powerful as it is secure to host your content and grow your business? Explore Postion and experience the peace of mind and convenience built for creators.