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77/100 SECURITY SCORE

Certificate Information

Subject
CN=livebook.dev
Issuer
C=US, O=Let's Encrypt, CN=E7
Valid From
September 29, 2025
Valid Until
December 28, 2025 55 days
Public Key
ECDSA 256 bit (P-256) Adequate
Signature Algorithm
ECDSA-SHA384
SHA-256 Fingerprint
86:38:60:C7:27:54:7D:6F:D5:D2:54:B2:19:47:F5:86:CC:31:C5:90:D3:F6:CA:D8:72:7E:37:22:7C:15:F6:CC
Alternative Names

Security Configuration

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

HTTP Security Headers

Status
Strict-Transport-Security
Present
max-age=31536000
Content-Security-Policy
Missing
Not configured
X-Frame-Options
Missing
Not configured
X-Content-Type-Options
Missing
Not configured
Referrer-Policy
Missing
Not configured
Permissions-Policy
Missing
Not configured
Recommendations
  • Increase HSTS max-age to at least 1 year and add includeSubDomains
  • Add Content-Security-Policy header to prevent XSS attacks
  • Add X-Frame-Options: DENY or SAMEORIGIN to prevent clickjacking
  • Add X-Content-Type-Options: nosniff
  • Add Referrer-Policy header (recommended: strict-origin-when-cross-origin)
  • Consider adding Permissions-Policy to control browser features

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

Subject Alternative Names

2 domains