Overview
Findings
Actions
Details
Related
AI-Generated Summary
What this means
developer.mozilla.org scored 82/100, demonstrating a strong security posture. Minor improvements are noted below.
Critical gaps in: DMARC / Email Security. Positive signals: MX Records & Mail Provider, TLS Protocol Support, TLS Configuration all passed.
2 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 developer.mozilla.org compares
Grade distribution across 2445 companies we've scanned. developer.mozilla.org scores better than 72% of them.
75
A+
24
A
180
A-
187
B+
71
B
342
B-
118
C+
112
C
308
C-
114
D+
93
D
226
D-
595
F
developer.mozilla.org — Grade B- (82/100)
2445 companies scanned
Security checks
Each check inspects a different part of developer.mozilla.org's public security setup. Green means healthy, yellow needs attention, red is a problem.
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).
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.
DNS CAA Records
No CAA records found. Without CAA, any Certificate Authority can issue certificates for this domain. Adding CAA records restricts issuance to authorized CAs only, reducing the risk of misissued certificates.
DNS Configuration
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.
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.
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.
TLS Configuration
TLSv1.3 negotiated with TLS_AES_128_GCM_SHA256 (128-bit). Strong configuration with no deprecated protocols or weak ciphers detected.
HSTS Header
HSTS enabled: max-age=63072000s (730 days). Missing includeSubDomains — subdomains not covered. Missing preload directive.
Security Headers
4/5 security headers present. Missing: Permissions-Policy.
Known Breaches
No known breaches found in public disclosure databases.
Cookie Security
No cookies set on the homepage response. No cookie security flags to evaluate.
CVE Exposure
Detected technologies: Google, Proxy/CDN. (Proxy/CDN detected but excluded from CVE matching — upstream infrastructure). No version information exposed — CVE matching not possible (this is good practice).
Certificate Hygiene
Strengths: Certificate valid, 80 days remaining; Issued by Let's Encrypt. Note: Wildcard certificate in use (*.domain) — covers all subdomains. Common practice; worth noting that compromise would affect all subdomains.
Recommended actions
2 items
Steps to improve developer.mozilla.org'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 developer.mozilla.org. This is the most common vector for phishing attacks targeting employees and customers. DMARC, SPF, DKIM are not configured.
Compliance impact
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
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2
Enable DNSSEC on your domain
Without DNSSEC, DNS responses for developer.mozilla.org can be spoofed, potentially redirecting users to malicious sites. This requires coordination with your domain registrar to publish DS records.
Compliance impact
NIST 800-53SC-20
Secure name/address resolution service
How to fix this
1
Check if your DNS provider supports DNSSEC (Cloudflare, Route53, etc.)
2
Enable DNSSEC signing in your DNS provider dashboard
3
Add the DS record to your registrar for .org TLD
4
Verify: dig +dnssec developer.mozilla.org
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
4/5 present
Missing: Permissions-Policy
HSTS
Enabled
HSTS enabled: max-age=63072000s (730 days). Missing includeSubDomains — subdomains not covered. Missing preload directive.
SSL Certificate
Valid
Strengths: Certificate valid, 80 days remaining; Issued by Let's Encrypt. 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.