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SECURITY SCORE
Certificate Information
Subject
CN=readthedocs.org
Issuer
C=US, O=Google Trust Services, CN=WE1
Valid From
October 24, 2025
Valid Until
January 22, 2026
80 days
Public Key
ECDSA
256 bit
(P-256)
Adequate
Signature Algorithm
ECDSA-SHA256
SHA-256 Fingerprint
08:12:34:27:BE:FC:CE:83:3B:7B:46:94:E2:B9:DC:76:58:C5:64:E5:BB:68:89:FF:F4:0F:47:11:3C:75:96:0F
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
Good
nosniff
Referrer-Policy
Good
no-referrer-when-downgrade
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
- • 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