Security checks — sorted by severity
DMARC / Email Security
Issues: No DMARC record found — email spoofing is not prevented; No SPF record found; No DKIM records found for common selectors (domain may use custom selectors — this is not a confirmed gap).
Issues: No DMARC record found — email spoofing is not prevented; No SPF record found; No DKIM records found for common selectors (domain may use custom selectors — this is not a confirmed gap).
HSTS Header
Strict-Transport-Security header is missing. Connections can be downgraded to HTTP via man-in-the-middle attacks.
Strict-Transport-Security header is missing. Connections can be downgraded to HTTP via man-in-the-middle attacks.
Security Headers
1/5 security headers present. Missing: X-Content-Type-Options, X-Frame-Options, Referrer-Policy, Permissions-Policy. This exposes the application to clickjacking, MIME-sniffing, and other client-side attacks.
1/5 security headers present. Missing: X-Content-Type-Options, X-Frame-Options, Referrer-Policy, Permissions-Policy. This exposes the application to clickjacking, MIME-sniffing, and other client-side attacks.
MTA-STS & TLS Reporting
Issues: No MTA-STS configured — email in transit is vulnerable to TLS downgrade attacks. Sending servers cannot verify that your mail server requires TLS; No TLSRPT record — TLS delivery failures won't be reported to domain owner.
Issues: No MTA-STS configured — email in transit is vulnerable to TLS downgrade attacks. Sending servers cannot verify that your mail server requires TLS; No TLSRPT record — TLS delivery failures won't be reported to domain owner.
DNS CAA Records
Strengths: CAA records configured (6 record(s)); Authorized CAs: digicert.com, letsencrypt.org, sectigo.com. Issues: No iodef record — CA violations won't be reported to the domain owner.
Strengths: CAA records configured (6 record(s)); Authorized CAs: digicert.com, letsencrypt.org, sectigo.com. Issues: No iodef record — CA violations won't be reported to the domain owner.
DNS Configuration
Issues: No NS records found (unusual); DNSSEC not configured — DNS responses can be spoofed.
Issues: No NS records found (unusual); DNSSEC not configured — DNS responses can be spoofed.
security.txt (RFC 9116)
No security.txt found. Publishing a security.txt at /.well-known/security.txt is the industry standard (RFC 9116) for vulnerability disclosure policies. Its absence may indicate a less mature security program.
No security.txt found. Publishing a security.txt at /.well-known/security.txt is the industry standard (RFC 9116) for vulnerability disclosure policies. Its absence may indicate a less mature security program.
Certificate Hygiene
Strengths: Issued by Let's Encrypt. Issues: Certificate expires in 27 days — renewal recommended soon. Note: Wildcard certificate in use (*.domain) — covers all subdomains. Common practice; worth noting that compromise would affect all subdomains.
Strengths: Issued by Let's Encrypt. Issues: Certificate expires in 27 days — renewal recommended soon. Note: Wildcard certificate in use (*.domain) — covers all subdomains. Common practice; worth noting that compromise would affect all subdomains.
MX Records & Mail Provider
No MX records found. This domain does not receive email directly — this is intentional for many domains and carries no security risk. If email is expected, verify mail routing via A/AAAA fallback or a mail provider.
No MX records found. This domain does not receive email directly — this is intentional for many domains and carries no security risk. If email is expected, verify mail routing via A/AAAA fallback or a mail provider.
TLS Protocol Support
Strengths: TLS 1.3 supported; TLS 1.2 supported; TLS 1.3 supported (strongest). Protocol support: TLS 1.3: Yes, TLS 1.2: Yes, TLS 1.1: No, TLS 1.0: No.
Strengths: TLS 1.3 supported; TLS 1.2 supported; TLS 1.3 supported (strongest). Protocol support: TLS 1.3: Yes, TLS 1.2: Yes, TLS 1.1: No, TLS 1.0: No.
TLS Configuration
TLSv1.3 negotiated with TLS_AES_128_GCM_SHA256 (128-bit). Strong configuration with no deprecated protocols or weak ciphers detected.
TLSv1.3 negotiated with TLS_AES_128_GCM_SHA256 (128-bit). Strong configuration with no deprecated protocols or weak ciphers detected.
Cookie Security
No cookies set on the homepage response. No cookie security flags to evaluate.
No cookies set on the homepage response. No cookie security flags to evaluate.
Known Breaches
No known breaches found in public disclosure databases.
No known breaches found in public disclosure databases.
CVE Exposure
Detected technologies: GitHub.com, Proxy/CDN. (Proxy/CDN detected but excluded from CVE matching — upstream infrastructure). No version information exposed — CVE matching not possible (this is good practice).
Detected technologies: GitHub.com, Proxy/CDN. (Proxy/CDN detected but excluded from CVE matching — upstream infrastructure). No version information exposed — CVE matching not possible (this is good practice).
Recommended actions
1+ items
Steps to improve google-developer-training.github.io's security grade, ranked by impact.
1
Set up email authentication (DMARC, SPF, DKIM)
Without email authentication, anyone can send emails that appear to come from google-developer-training.github.io. This is the most common vector for phishing attacks targeting employees and customers. DMARC, SPF, DKIM are not configured.
NIST CSFPR.AC-7
Email authentication is a required access control
ISO 27001A.13.2.1
Information transfer policies require email security controls
HIPAA§164.312(e)
Transmission security for electronic PHI
How to fix this
1
Add SPF record to DNS: v=spf1 include:_spf.google.com ~all (adjust for your email provider)
2
Configure DKIM signing with your email provider and publish the public key in DNS
3
Add DMARC record: v=DMARC1; p=quarantine; rua=mailto:[email protected]
4
Monitor DMARC reports for 2–4 weeks, then upgrade policy to p=reject
See all 4 remaining recommendations
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AI Summary
What this means
google-developer-training.github.io scored 57/100 and does not meet the minimum security posture threshold. The most critical issue is: Set up email authentication (DMARC, DKIM). This must be addressed before the vendor can be approved for procurement or data processing activities.
Critical gaps in: HSTS Header, Security Headers, DMARC / Email Security. Positive signals: MX Records & Mail Provider, TLS Protocol Support, TLS Configuration all passed.
5 action items identified, including 1 critical. The issues are configuration gaps, not architectural problems. A focused remediation effort of 2–5 days could address all findings.
How google-developer-training.github.io compares
Grade distribution across 2678 companies we've scanned. google-developer-training.github.io scores better than 18% of them.
88
A+
28
A
194
A-
200
B+
75
B
376
B-
137
C+
117
C
347
C-
123
D+
96
D
265
D-
632
F
google-developer-training.github.io — Grade F (57/100)
2678 companies scanned
At a glance
Key data points from the scan.
TLS Version
TLSv1.3
TLSv1.3 negotiated with TLS_AES_128_GCM_SHA256 (128-bit). Strong configuration with no deprecated protocols or weak ciphers detected.
DMARC Policy
Not configured
Issues: No DMARC record found — email spoofing is not prevented; No SPF record found; No DKIM records found for common selectors (domain may use custom selectors — this is not a confirmed gap).
SPF Record
Missing
No SPF record found.
Security Headers
1/5 present
Missing: X-Content-Type-Options, X-Frame-Options, Referrer-Policy, Permissions-Policy
HSTS
Not enabled
Strict-Transport-Security header is missing. Connections can be downgraded to HTTP via man-in-the-middle attacks.
SSL Certificate
Issues
Strengths: Issued by Let's Encrypt. Issues: Certificate expires in 27 days — renewal recommended soon. Note: Wildcard certificate in use (*.domain) — covers all subdomains. Common practice; worth noting that compromise would affect all subdomains.
DNSSEC
Not enabled
Issues: No NS records found (unusual); DNSSEC not configured — DNS responses can be spoofed.
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