DNS Gurus
Open Cached · just now
86/100 SECURITY SCORE

Certificate Information

Subject
CN=appnexus.com
Issuer
C=US, O=Let's Encrypt, CN=R12
Valid From
November 01, 2025
Valid Until
January 30, 2026 87 days
Public Key
RSA 2048 bit Adequate
Signature Algorithm
SHA256-RSA
SHA-256 Fingerprint
80:A9:D8:CA:DA:18:78:FB:28:32:CB:91:2E:9F:4A:01:C2:22:2E:A4:82:5A:BA:61:8A:80:B3:FA:B5:B7:D3:34
Alternative Names
7 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
Present
max-age=63072000; includeSubdomains; preload
Content-Security-Policy
Basic
default-src; script-src; style-src; +5 more
X-Frame-Options
Good
SAMEORIGIN
X-Content-Type-Options
Good
nosniff
Referrer-Policy
Missing
Not configured
Permissions-Policy
Missing
Not configured
Recommendations
  • • Increase HSTS max-age to at least 1 year and add includeSubDomains
  • • Improve CSP by adding more specific directives and removing 'unsafe-inline'
  • • 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