DNS Gurus
Cached · just now
92/100 SECURITY SCORE

Certificate Information

Subject
CN=serceo.pl
Issuer
C=US, O=Let's Encrypt, CN=E8
Valid From
December 22, 2025
Valid Until
March 22, 2026 46 days
Public Key
ECDSA 256 bit (P-256) Adequate
Signature Algorithm
ECDSA-SHA384
SHA-256 Fingerprint
8D:F5:77:0D:A2:7D:97:34:E5:B8:6F:DB:2D:0E:A8:69:9A:4D:CE:4C:DA:B6:0F:FD:B8:E0:2F:53:0A:2F:F5:F8
Alternative Names
6 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
Good
connect-src; img-src; media-src; +9 more
X-Frame-Options
Good
SAMEORIGIN
X-Content-Type-Options
Good
nosniff
Referrer-Policy
Good
no-referrer
Permissions-Policy
Missing
Not configured
Recommendations
  • • Consider adding 'preload' to HSTS for maximum security
  • • Strengthen CSP by removing 'unsafe-eval'
  • • 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