Open
Cached
·
just now
89/100
SECURITY SCORE
Detected Technologies
Certificate Information
Subject
CN=gitbook.io
Issuer
C=US, O=Google Trust Services, CN=WE1
Valid From
March 21, 2026
Valid Until
June 19, 2026
43 days
Public Key
ECDSA
256 bit
(P-256)
Adequate
Signature Algorithm
ECDSA-SHA256
SHA-256 Fingerprint
E4:C8:8E:DD:4D:AF:02:E9:0C:07:84:4A:BF:2A:E5:1F:F5:C2:E9:F0:5F:3F:9C:B0:9C:27:FC:9E:A6:34:FA:42
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
Present
max-age=31536000
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
- • Increase HSTS max-age to at least 1 year and add includeSubDomains
- • Improve CSP by adding more specific directives and removing 'unsafe-inline'
- • 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
Configured
(Restricts certificate issuance)
Current Issuer
Authorized
(Matches CAA policy)
Authorized CAs
Recommendations
- • Consider using critical flag (flags=128) for stricter CAA enforcement
- • Consider adding 'iodef' records to receive notifications about unauthorized certificate issuance attempts
- • Consider adding 'issuewild' records to control wildcard certificate issuance