DNS Gurus
Open Cached · just now
75/100 SECURITY SCORE

Certificate Information

Subject
CN=cs124.org
Issuer
C=US, O=Let's Encrypt, CN=E7
Valid From
November 21, 2025
Valid Until
February 19, 2026 89 days
Public Key
ECDSA 256 bit (P-256) Adequate
Signature Algorithm
ECDSA-SHA384
SHA-256 Fingerprint
D9:21:19:A0:8B:69:02:F0:49:97:A1:13:EC:63:ED:0B:E5:4C:40:67:16:CA:E5:E0:3F:0A:32:B1:BC:8B:D6:D2
Alternative Names
31 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
Missing
Not configured
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
  • • Add Strict-Transport-Security header with max-age of at least 1 year
  • • 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