Overview
Findings
Actions
Details
Related
AI-Generated Summary
What this means
linode.com scored 88/100, demonstrating a strong security posture. Minor improvements are noted below.
Critical gaps in: Security Headers. Positive signals: MX Records & Mail Provider, TLS Configuration, HSTS Header all passed.
2 action items identified, including 0 critical. The issues are configuration gaps, not architectural problems. A focused remediation effort of 2–5 days could address all findings.
How linode.com compares
Grade distribution across 2445 companies we've scanned. linode.com scores better than 81% 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
linode.com — Grade B+ (88/100)
2445 companies scanned
Security checks
Each check inspects a different part of linode.com's public security setup. Green means healthy, yellow needs attention, red is a problem.
Security Headers
None of the 5 recommended security headers are present (missing: CSP, 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.
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
Strengths: 6 nameservers configured (a16-64.akam.net., a3-67.akam.net., a7-65.akam.net., a12-65.akam.net.); 2 MX records present; Zone transfers properly restricted. Issues: 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
Strengths: Mail handled by Proofpoint; 2 MX record(s) configured; Multiple MX records provide redundancy; Equal-priority MX records (10) — standard round-robin load balancing for Proofpoint.
TLS Configuration
TLSv1.3 negotiated with TLS_AES_256_GCM_SHA384 (256-bit). Strong configuration with no deprecated protocols or weak ciphers detected.
HSTS Header
HSTS enabled: max-age=31536000s (365 days). Missing includeSubDomains — subdomains not covered. Missing preload directive.
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.
Cookie Security
No cookies set on the homepage response. No cookie security flags to evaluate.
CVE Exposure
No server software versions detected in HTTP response headers. This is good practice (version hiding) but means CVE exposure cannot be assessed from external signals alone.
DMARC / Email Security
Strengths: DMARC policy set to reject (strongest); SPF record present with hard-fail (-all); DKIM configured (selectors: k1).
Known Breaches
No known breaches found in public disclosure databases.
Certificate Hygiene
Strengths: Certificate valid, 84 days remaining; Issued by Let's Encrypt.
Recommended actions
2 items
Steps to improve linode.com's security grade, ranked by impact.
1
Add missing security headers (CSP, X-Content-Type-Options, X-Frame-Options, Referrer-Policy, Permissions-Policy)
5 of 5 recommended security headers are missing on linode.com: CSP, X-Content-Type-Options, X-Frame-Options, Referrer-Policy, Permissions-Policy. These headers protect against clickjacking, MIME-sniffing, and unauthorized browser feature access. Adding them is a server configuration change with no application code changes required.
Compliance impact
PCI-DSS 4.0Req 6.4.1
Security headers are required application controls
OWASPSecure Headers
Recommended baseline for web applications
How to fix this
1
Add a Content-Security-Policy header. Safe starting value (works with Google Fonts and inline styles/scripts): default-src 'self'; style-src 'self' 'unsafe-inline' https://fonts.googleapis.com; font-src 'self' https://fonts.gstatic.com; script-src 'self' 'unsafe-inline'; upgrade-insecure-requests. Test your site after adding it, then tighten over time by removing 'unsafe-inline'.
2
Add: X-Content-Type-Options: nosniff
3
Add: X-Frame-Options: SAMEORIGIN (use DENY only if you never embed your pages in iframes)
4
Add: Referrer-Policy: strict-origin-when-cross-origin
5
Add: Permissions-Policy: camera=(), microphone=(), geolocation=()
6
Verify with: curl -sI https://linode.com | grep -iE 'content-security|x-frame|x-content|referrer|permissions'
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2
Enable DNSSEC on your domain
Without DNSSEC, DNS responses for linode.com 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 .com TLD
4
Verify: dig +dnssec linode.com
At a glance
Key data points from the scan.
TLS Version
TLSv1.3
TLSv1.3 negotiated with TLS_AES_256_GCM_SHA384 (256-bit). Strong configuration with no deprecated protocols or weak ciphers detected.
DMARC Policy
p=reject
Strengths: DMARC policy set to reject (strongest); SPF record present with hard-fail (-all); DKIM configured (selectors: k1).
SPF Record
Present
v=spf1 a:outbound.mail.linode.com include:sendersv4b.mail.linode.com include:_spf.google.com include
Security Headers
0/5 present
Missing: CSP, X-Content-Type-Options, X-Frame-Options, Referrer-Policy, Permissions-Policy
HSTS
Enabled
HSTS enabled: max-age=31536000s (365 days). Missing includeSubDomains — subdomains not covered. Missing preload directive.
SSL Certificate
Valid
Strengths: Certificate valid, 84 days remaining; Issued by Let's Encrypt.
DNSSEC
Not enabled
Strengths: 6 nameservers configured (a16-64.akam.net., a3-67.akam.net., a7-65.akam.net., a12-65.akam.net.); 2 MX records present; Zone transfers properly restricted. Issues: DNSSEC not configured — DNS responses can be spoofed.