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Security report for holidu.dk

Holidu GmbH · Hospitality · Denmark

Medium risk. 5 critical or high findings in GDPR outside view, Security headers and 1 other check.

Security score

73/100

Risk levelMedium

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

Holidu GmbH operates a professional online vacation rental platform specializing in holiday homes, apartments, and summer houses across Europe, with a strong presence in Denmark. The company offers a price guarantee and targets families, pet owners, and travelers seeking quality accommodations. Their market position is that of a specialist with a comprehensive portfolio and a user-friendly booking experience, supported by a mobile app. Technically, the website uses modern frameworks like React and Tailwind CSS, integrates multiple analytics and marketing tools, and demonstrates good SEO and accessibility practices. Security-wise, the site enforces HTTPS, employs standard security headers, and provides cookie consent mechanisms, though it lacks explicit security.txt and incident response disclosures. Overall, the site is trustworthy, professionally designed, and compliant with GDPR, but could improve transparency in security policies and contact information.

Scanned

NIS2 and GDPR posture

GDPR outside view
33/ 100 · High
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

5 findings rated critical or high. Fix these first.

  1. GDPR outside view

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

    • Critical

      EU business without adequate privacy measures

      EU businesses are subject to strict GDPR requirements

      What to do: Implement comprehensive GDPR compliance including privacy policy, cookie consent, and data protection measures

    • 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

  2. 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 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';…

  3. SSL/TLS

    TLS encrypts the connection and proves the site is really yours. Weak or expiring certificates trigger browser warnings and put traffic at risk.

    • High

      Weak Protocols Supported

      Server supports weak protocols: TLSv1.1

      What to do: Disable TLS 1.0, TLS 1.1, and all SSL versions

      • CWE-327
      • OWASP A04:2025
      • ASVS V12.1.1

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

Keep watching holidu.dk

This scan found 17 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.

Daily monitoring

Recommended

€25per month

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

Email alerts on material changes and an exportable JSON history of every change.

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Full report

€39.90one-time

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Prices incl. 21% VAT. Secure checkout by Mollie; sold by SEQ SIA, Latvia.

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
72
Security headers
70
Email security
80
DNS health
85
Network security
100
GDPR outside view
33
Average
73

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

Technical appendix

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

Business context

Business profile

Holidu's business model centers on aggregating vacation rental listings and providing a seamless booking experience with a price guarantee, appealing to European travelers. Their competitive advantage lies in specialization and a broad geographic reach with localized sites. Revenue likely derives from commissions on bookings and partnerships. The target customers include families, pet owners, and vacationers seeking diverse property types. The company maintains a strong partnership ecosystem with localized domains and integrates major advertising and analytics platforms. Growth indicators include mobile app availability and extensive property listings. Strategic observations suggest focusing on enhancing direct contact channels and security transparency to strengthen customer trust.

Security posture

The website demonstrates a mature security posture with HTTPS enforcement, no visible sensitive data exposure, and cookie consent aligned with GDPR. However, it lacks published security policies, incident response contacts, and a vulnerability disclosure program, which are important for comprehensive security governance. The absence of a security.txt file and explicit security framework references indicates room for improvement. No vulnerabilities or suspicious activities were detected in the content. The use of third-party tracking and advertising services is balanced with privacy compliance measures. Overall, the security maturity is good but could be enhanced by formalizing security communication and disclosure practices.

Recommendations

  1. Implement and publish a security.txt file to facilitate vulnerability reporting.
  2. Add explicit incident response and security policy pages with contact information.
  3. Enhance HTTP security headers by adding Content Security Policy and HSTS.
  4. Provide clear company contact details including phone and email on the website.
  5. Regularly audit third-party scripts and tracking tools for privacy and security compliance.
Site observations

Automated reading of the public site. Ratings are indicative.

Business

Company
Holidu GmbH
Description
Stort udvalg af feriehuse, ferielejligheder og sommerhuse af høj kvalitet med prisgaranti. Specialist i ferieboliger med pool, havudsigt, børnevenlige eller kæledyrsvenlige i de smukkeste ferieregioner i Europa.
Key services
Vacation home and apartment rentals, Price guarantee, Booking platform, Mobile app for bookings
Content quality
excellent
Branding
consistent

Technology

Stack
JavaScript, React, Tailwind CSS, ThumbmarkJS, Google Tag Manager, Google Analytics, Taboola, Bing Ads, Facebook Connect
Frameworks
React
Platforms
Web, Mobile (iOS and Android apps)
Performance
moderate
Mobile
excellent
Accessibility
good
SEO
good

Security

Observed score
85/100
Good practices seen
  • HTTPS enforced
  • No exposed sensitive data in HTML
  • Cookie consent mechanism present
  • Secure forms with POST method for redirects

Analytics and tracking

Services
Google Analytics
Tracking level
moderate
Privacy practices
good

Advertising

Ad networks
Taboola, Bing Ads, Facebook Ads
Tracking pixels
Facebook Connect, Bing Ads
Transparency
good

Site quality

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

Key observations

  1. Website is a professional vacation rental platform targeting Danish and European customers.
  2. Content is rich with property listings and user ratings.
  3. Privacy and cookie policies are present and GDPR compliant.
  4. No direct contact emails or phone numbers found on the homepage.
  5. WHOIS data is unavailable, indicating privacy protection.
  6. No security challenges or WAF blocks detected.
  7. Uses modern web technologies and tracking tools.
  8. Good SEO and accessibility practices observed.
Technical notes

Notes

The website is built on a modern JavaScript stack using React and Tailwind CSS, ensuring responsive and accessible design. It leverages CDN services for assets and fonts, and integrates analytics and marketing tools such as Google Analytics, Google Tag Manager, Taboola, Bing Ads, and Facebook Connect. Performance is moderate with asynchronous script loading and font optimization. The site uses secure forms for redirects and maintains SEO best practices with comprehensive meta tags and Open Graph data. Technical risks are minimal, but the absence of a CMS identification and hosting provider details limits full infrastructure assessment. Opportunities exist to improve security headers and formalize security disclosures.
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. 72/100Medium26 findingsView report
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