DNS Gurus
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91/100 SECURITY SCORE

Certificate Information

Subject
CN=tellow.nl
Issuer
C=US, O=Let's Encrypt, CN=E8
Valid From
October 17, 2025
Valid Until
January 15, 2026 54 days
Public Key
ECDSA 256 bit (P-256) Adequate
Signature Algorithm
ECDSA-SHA384
SHA-256 Fingerprint
4D:2B:CC:99:77:94:F2:6C:E0:5D:1E:21:45:2B:5D:C6:86:58:22:E3:41:E2:38:7A:D7:D3:C6:72:F9:71:16:6E
Alternative Names
13 domains

Security Configuration

TLS Protocols
TLS 1.2 TLS 1.3
Forward Secrecy
Supported (Modern clients use PFS)

HTTP Security Headers

Status
Strict-Transport-Security
Good
max-age=31536000; includeSubDomains
Content-Security-Policy
Weak
upgrade-insecure-requests
X-Frame-Options
Excellent
DENY
X-Content-Type-Options
Good
nosniff
Referrer-Policy
Good
strict-origin-when-cross-origin
Permissions-Policy
Present
geolocation=(), microphone=(), camera=(), payment=()
Recommendations
  • • Consider adding 'preload' to HSTS for maximum security
  • • Significantly strengthen CSP directives

CAA Records (Certificate Authority Authorization)

CAA Records
Not Configured (Any CA can issue certificates)
CAA Issues
  • • No CAA records configured - any CA can issue certificates
Recommendations
  • • Implement CAA records to restrict which CAs can issue certificates for your domain
  • • This adds an extra layer of security against unauthorized certificate issuance
  • • Example: Add CAA record 'example.com. CAA 0 issue "letsencrypt.org"'
  • • Consider adding 'iodef' record to receive security incident reports