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Security report for caddyserver.com

ZeroSSL · Technology · N/a

Medium risk. 6 critical or high findings in Security headers, GDPR outside view and 1 other check.

Security score

61/100

Risk levelMedium

0–100, higher is better. How it is calculated

Caddyserver.com represents the official website for Caddy, an advanced open source web server developed in Go, specializing in automatic HTTPS and TLS certificate management. The project is backed by ZeroSSL and enjoys sponsorship from prominent technology companies such as Stripe and Mercedes-Benz. The website targets developers, enterprises, and SaaS providers seeking secure, scalable, and reliable web server solutions. It offers a modular, extensible platform with features including internal PKI management, reverse proxy capabilities, and PHP application hosting via FrankenPHP. The site demonstrates a high level of technical maturity with modern web technologies, fast performance, and excellent mobile optimization. Security is a core focus, with compliance to PCI, HIPAA, and NIST standards, automatic certificate renewal, and advanced TLS features. However, the site lacks explicit privacy and cookie policies, as well as direct contact information, which are areas for improvement in compliance and user trust. Overall, the website is professional, trustworthy, and well-positioned in the technology market.

Scanned

NIS2 and GDPR posture

GDPR outside view
58/ 100 · Medium
Checks completed
7of 7

NIS2 Art. 21(2)

  1. (a) Risk analysis and security policies: Not visible from outside
  2. (b) Incident handling: One indicator
  3. (c) Business continuity, backups and crisis management: Not visible from outside
  4. (d) Supply chain security: Not visible from outside
  5. (e) Secure acquisition, development and maintenance, including vulnerability handling: Partly checked
  6. (f) Assessing the effectiveness of security measures: Not visible from outside
  7. (g) Cyber hygiene and security training: Not visible from outside
  8. (h) Cryptography and encryption: Partly checked
  9. (i) HR security, access control and asset management: One indicator
  10. (j) Multi-factor authentication and secured communications: Not visible from outside

This scan rated NIS2 with an earlier keyword method that is no longer shown; rescan for the per-article view. Risk management, continuity, supply chain, training, MFA, management oversight (Art. 20) and incident reporting (Art. 23) need internal evidence, and Guard cannot tell whether NIS2 applies to this organisation.

GDPR is indicative only, based on publicly visible signals: Articles 7, 12, 13 and 32 of Regulation (EU) 2016/679 and Article 5(3) of the ePrivacy Directive. Not a certification or legal assessment.

Priority findings

6 findings rated critical or high. Fix these first.

  1. Security headers

    Security headers are instructions your web server sends to every visitor’s browser. Missing ones leave visitors more exposed to attacks such as clickjacking and injected scripts.

    • High

      Missing Strict-Transport-Security header

      Forces HTTPS connections

      What to do: Add "Strict-Transport-Security: max-age=31536000; includeSubDomains; preload"

      • CWE-319
      • OWASP A04:2025
      • ASVS V3.4.1
    • High

      Missing X-Frame-Options header

      Prevents clickjacking attacks

      What to do: Add "X-Frame-Options: DENY" or "X-Frame-Options: SAMEORIGIN"

    • High

      Missing Content-Security-Policy header

      Controls resources the browser is allowed to load

      What to do: Implement a Content-Security-Policy appropriate for your application

      • ASVS V3.4.3
      • OWASP Secure Headers: OWASP Secure Headers Project recommends Content-Security-Policy: default-src 'self'; form-action 'self'; base-uri 'self'; object-src 'none';…

  2. GDPR outside view

    These are the privacy signals visitors and data protection authorities look for under GDPR.

    • High

      No Cookie Policy found

      GDPR requires clear information about cookie usage

      What to do: Add a dedicated cookie policy explaining cookie usage and purposes

    • High

      No Cookie Consent Banner found

      GDPR requires explicit consent for non-essential cookies

      What to do: Implement a cookie consent banner that appears on first visit

Need hands-on remediation? Email guard@offseq.com

Keep watching caddyserver.com

This scan found 20 issues across 6 checks. Monitoring re-runs those checks daily, emails you when something material changes and records each fix, so you can show progress.

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  • TLS certificates and expiry
  • DNS records
  • SPF, DKIM and DMARC
  • Security headers
  • GDPR and NIS2 posture
  • Exposed services
  • Third-party trackers
  • Security score drift

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Results by check

Each check with its score, findings and the evidence it collected.

How this score is calculated

The security score runs 0–100, higher is better. It is the plain average of the security checks that completed in this scan, each counted equally. A check that could not run is left out: it counts neither as a pass nor as a fail.

Counted in this score

SSL/TLS
75
Security headers
15
Email security
85
DNS health
90
Network security
40
GDPR outside view
58
Average
61

Not counted

  • NIS2 outside view: Re-weights evidence from the TLS, email, DNS, network and hygiene checks, so counting it would count that evidence twice. Shown on its own.
  • OffSeq Observations: An AI reading of the site, useful context but not reproducible evidence. Shown on its own.

Findings that cap the score at 49

Each of these is serious on its own, so while any is present the site cannot rate better than high risk, however good the other checks are.

  • The certificate is not trusted by browsers
  • The website is not served over HTTPS
  • A database, remote desktop, file-sharing or Telnet service is reachable from the internet
  • The page loads a script from a compromised source
  • The domain registration has expired
  • SPF authorises every server to send mail as the domain

Partial scans

When the site blocks Guard or most checks cannot run, the score covers only the checks that ran (usually DNS and email), is capped at 75 and is shown as partial, without a risk level.

Risk levels

  • Critical0–25
  • High26–49
  • Medium50–75
  • Low76–100

Breach exposure

Leaked credentials and lookalike domains from OffSeq Breach. The counts are free; the detailed lists are paid add-ons.

Dark web exposure

Add-on

Leaked records that mention caddyserver.com, from OffSeq Breach.

Total records
100
Employees
0
Customers
100
Third parties
0
Weak passwords
9%

1 subdomain affected

See the 10 newest leaked credentials

A one-off add-on to this report that lists the most recent identifier and password pairs OffSeq Breach holds for caddyserver.com.

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Technical appendix

Business context, site observations and technical notes gathered during the scan, and the standards behind each reference.

Business context

Business profile

Caddy operates as an essential technology entity within the web server and security infrastructure sector. Its open source business model is supported by sponsorships and enterprise services, enabling sustainable development and innovation. The project has a strong competitive advantage due to its automatic HTTPS capabilities, modular architecture, and compliance with major security standards. The target customer segments include developers, SaaS companies, and enterprises requiring scalable and secure web infrastructure. The partnership ecosystem includes ZeroSSL and other industry leaders, enhancing credibility and reach. Growth indicators include extensive community engagement, academic citations, and adoption by high-profile sponsors. Strategic observations highlight the importance of expanding compliance documentation and enhancing direct communication channels to further solidify market trust.

Security posture

Caddy demonstrates a mature security posture with robust TLS management, automatic certificate issuance and renewal, and advanced features like OCSP stapling and cluster coordination. The use of Go, a memory-safe language, reduces common vulnerabilities. Compliance with PCI, HIPAA, and NIST frameworks is explicitly stated, indicating alignment with industry best practices. However, the absence of a published security policy, incident response contacts, and vulnerability disclosure mechanisms represents gaps in transparency and readiness. No vulnerabilities or exposed sensitive data were detected in the website content. The security score is high, but improvements in policy publication and contact availability would enhance incident response and trust.

Recommendations

  1. Publish a comprehensive privacy policy and cookie policy with clear consent mechanisms to improve GDPR and privacy compliance.
  2. Add explicit security policy documentation and provide dedicated incident response contact channels (e.g., security@ or abuse@ emails).
  3. Implement and link to a vulnerability disclosure policy or security.txt file to encourage responsible reporting.
  4. Include clear and accessible contact information for general and security inquiries to enhance user trust and support.
  5. Add security headers such as Content-Security-Policy, X-Frame-Options, and Strict-Transport-Security to strengthen HTTP security posture.
Site observations

Automated reading of the public site. Ratings are indicative.

Business

Company
ZeroSSL
Description
Caddy is a powerful, enterprise-ready, open source web server with automatic HTTPS written in Go. It offers automatic TLS certificate management, internal PKI capabilities, and a modular architecture for extensibility.
Key services
Automatic HTTPS with TLS certificate management, Internal PKI and private CA management, Reverse proxy with load balancing and health checks, Static file serving with advanced features, Extensible modular architecture, PHP application server integration (FrankenPHP)
Content quality
excellent
Branding
consistent

Technology

Stack
Go (Golang), JSON configuration, RESTful API, Smallstep libraries, Asciinema player, Google Fonts, Google Analytics (gtag.js), Fathom Analytics
Performance
fast
Mobile
excellent
Accessibility
good
SEO
good

Security

Observed score
90/100
Good practices seen
  • Automatic HTTPS with certificate issuance and renewal
  • OCSP stapling and caching
  • On-Demand TLS for dynamic certificate provisioning
  • Cluster coordination for certificate management
  • Secure defaults meeting PCI, HIPAA, and NIST compliance
  • Memory-safe language (Go) used for development

Analytics and tracking

Services
Google Analytics, Fathom Analytics
Tracking level
moderate
Privacy practices
basic

Advertising

Marketing tools
Google Analytics (gtag.js), Fathom Analytics
Transparency
basic

Site quality

Design
excellent
User experience
excellent
Content relevance
excellent
Navigation
excellent
Professionalism
excellent
Trustworthiness
high

Key observations

  1. Website is fully accessible with rich content and no blocking.
  2. Strong emphasis on security and compliance with recognized standards.
  3. No explicit privacy or cookie policies found, which is a compliance gap.
  4. No direct contact information or forms found on the main page.
  5. Extensive use of modern web technologies and good performance indicators.
  6. Strong community and industry support visible through sponsors and testimonials.
  7. No suspicious or malicious content detected.
Technical notes

Notes

The website is built with modern web technologies including Go-based backend, JSON configuration, RESTful APIs, and integration with Smallstep libraries for PKI. Frontend technologies include Google Fonts, Asciinema player for demos, and analytics tools like Google Analytics and Fathom. The site is well-structured with semantic HTML, responsive design, and good SEO practices. Performance is optimized with compression and caching strategies. No CMS is detected, indicating a custom or static site approach. Hosting details are not explicit but likely cloud-based. Technical risks are minimal, with no deprecated or vulnerable libraries detected. Opportunities exist to enhance security headers and compliance documentation to reduce technical debt and improve operational resilience.
Standards and sources

Reference chips under each finding point to the standard, regulation or specification the finding relates to. They are taken from the official datasets below and mapped conservatively: a finding with no defensible link shows none. NIS2 and GDPR references mark where a finding is relevant evidence, not a compliance verdict. Implementing Regulation (EU) 2024/2690 binds digital infrastructure and digital service providers; for other entities it is the most detailed public reading of the Article 21 measures. WCAG, EN 301 549, European Accessibility Act and Web Accessibility Directive references name the requirement an automated accessibility rule relates to; they are not a conformance verdict.

Retrieved 2026-10-25

Earlier scans of this domain

  1. 61/100Medium28 findingsView report
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