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Security report for grena.cz

GRENA, a.s. · Manufacturing · Czech Republic

High risk. 10 critical or high findings in GDPR outside view, Security headers and 2 other checks.

Security score

45/100

Risk levelHigh

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

GRENA, a.s. is a Czech manufacturing company specializing in insulating vermiculite boards and fire-resistant materials, serving industrial and commercial sectors with a well-established market presence since 1999. Their website offers product information, e-commerce capabilities, and company news, targeting primarily Czech-speaking customers with some English support. The technical infrastructure uses modern web technologies including jQuery, Bootstrap, and Google Tag Manager, with a custom CMS by FlexiSystems. The site is mobile-optimized and SEO-friendly, though accessibility could be improved. Security posture is solid with HTTPS and cookie consent implemented, but lacks advanced security headers and explicit security policies. WHOIS data confirms domain legitimacy and long-term operation. Overall, the website is professional, trustworthy, and business-focused.

Scanned

NIS2 and GDPR posture

GDPR outside view
25/ 100 · Critical
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

10 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 Privacy Policy found

      GDPR requires a clear and accessible privacy policy

      What to do: Add a comprehensive privacy policy page and link to it prominently

  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 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';…

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Keep watching grena.cz

This scan found 25 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
52
Security headers
15
Email security
85
DNS health
75
Network security
20
GDPR outside view
25
Average
45

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

GRENA operates in the manufacturing sector, focusing on fire-resistant and insulating materials with a diversified product portfolio including panels, vermiculite products for gardening, and battery storage boxes. The company maintains a medium-sized operation with subsidiaries such as GRENAMAT and JAVAB. Their business model includes direct sales and e-commerce, supported by active social media channels and participation in industry events. The company demonstrates stable growth and market positioning in the Czech Republic, with clear contact channels and certifications enhancing credibility.

Security posture

The website employs HTTPS with a valid SSL configuration and uses Google Tag Manager for analytics and marketing. Cookie consent mechanisms are in place, indicating awareness of privacy compliance. However, the absence of security headers like Content-Security-Policy and lack of a public security policy or vulnerability disclosure reduce the overall security maturity. No critical vulnerabilities or exposed sensitive data were detected in the HTML content. Incident response contact information is not provided, which could be improved to enhance security readiness.

Recommendations

  1. Implement standard security headers such as Content-Security-Policy, X-Frame-Options, and X-Content-Type-Options to enhance protection against common web attacks.
  2. Publish a clear security policy and vulnerability disclosure program or security.txt file to improve transparency and incident response readiness.
  3. Enhance accessibility features to comply with WCAG standards for better user experience and inclusivity.
  4. Expand privacy policy details to explicitly address GDPR compliance and data retention policies.
  5. Regularly audit third-party scripts and libraries to ensure no vulnerable versions are in use.

Contact details published on the site

Addresses
Legal name
GRENA, a.s.
Site observations

Automated reading of the public site. Ratings are indicative.

Business

Company
GRENA, a.s.
Description
Dodáváme Izolační vermikulitové desky, žáruvzdorné, nehořlavé a protipožární materiály.
Key services
Production and supply of insulating vermiculite boards, Fire-resistant and non-flammable materials, Panels and board materials, Garden and animal care vermiculite products, E-commerce sales
Content quality
good
Branding
consistent

Technology

Stack
jQuery, Bootstrap, Slick Carousel, Google Tag Manager, FormValidation, Magnific Popup, jQuery UI, mCustomScrollbar, cookie-consent.min.js
Frameworks
Bootstrap
Performance
moderate
Mobile
good
Accessibility
basic
SEO
good

Security

Observed score
75/100
Good practices seen
  • HTTPS enforced
  • Google Tag Manager used asynchronously
  • Cookie consent implemented

Analytics and tracking

Services
Google Analytics (commented out), Google Tag Manager
Tracking level
moderate
Privacy practices
basic

Advertising

Transparency
basic

Site quality

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

Key observations

  1. Website is fully accessible and not blocked by WAF or security challenges.
  2. Content is primarily in Czech with some English language options.
  3. Business is manufacturing focused with e-commerce capabilities.
  4. Cookie consent is implemented with a visible management button.
  5. No explicit privacy policy page found but a certificates page exists which may contain quality and compliance info.
  6. No terms of service or security policy pages detected.
  7. Contact information is clearly presented including phone, email, physical address, and contact form.
  8. Social media presence is active on Facebook, Instagram, LinkedIn, and YouTube.
  9. Use of modern JavaScript libraries and frameworks for UI and analytics.
  10. No critical security issues or vulnerabilities detected in the HTML content.
Technical notes

Notes

The website is built on a custom CMS platform by FlexiSystems, utilizing popular JavaScript libraries such as jQuery, Bootstrap, Slick Carousel, and FormValidation for UI and form handling. Google Tag Manager is used for analytics and marketing tags. The site is responsive and mobile-friendly with moderate performance. SEO is supported by proper meta tags and structured navigation. There is room for improvement in accessibility and security header implementation. Hosting provider details are not explicitly identified from the content.
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

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