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SECURITY SCORE
Certificate Information
Subject
CN=zulip.com
Issuer
C=US, O=Amazon, CN=Amazon ECDSA 256 M02
Valid From
March 05, 2025
Valid Until
April 04, 2026
152 days
Public Key
ECDSA
256 bit
(P-256)
Adequate
Signature Algorithm
ECDSA-SHA256
SHA-256 Fingerprint
58:94:47:0D:C4:41:D8:2E:0B:F3:66:D8:C3:DA:8E:94:12:52:66:A1:9D:D8:18:21:8F:1E:AF:C7:68:E7:28:5B
Alternative Names
Security Configuration
TLS Protocols
TLS 1.2
Forward Secrecy
Limited
(Check cipher configuration)
Warnings
- • TLS 1.3 is not supported (recommended)
HTTP Security Headers
Status
Strict-Transport-Security
Present
max-age=15768000
Content-Security-Policy
Missing
Not configured
X-Frame-Options
Excellent
DENY
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
- • Add Content-Security-Policy header to prevent XSS attacks
- • 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
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