76/100 SECURITY SCORE

Certificate Information

Subject
CN=simulation.tudelft.nl
Issuer
C=AT, O=ZeroSSL, CN=ZeroSSL RSA Domain Secure Site CA
Valid From
October 11, 2025
Valid Until
January 09, 2026 67 days
Public Key
RSA 4096 bit Strong
Signature Algorithm
SHA384-RSA
SHA-256 Fingerprint
C2:73:62:9E:45:00:40:AC:00:56:F8:63:42:2F:52:28:EF:F5:C1:EF:71:F7:2E:97:FF:CC:34:C4:54:F1:1F:8D
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
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