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Security report for o-seznam.cz

Seznam.cz, a.s. · Technology · Czech Republic

Medium risk. 7 critical or high findings in GDPR outside view and Security headers.

Security score

61/100

Risk levelMedium

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

Seznam.cz, a.s. is a leading Czech internet company operating as the country's number one internet platform. The company manages over 30 services supported by more than 1,900 employees, including proprietary data centers and a broad portfolio of online services such as search, advertising, and media. The website 'O Seznamu' serves as a corporate information portal highlighting the company's vision, leadership, career opportunities, and social responsibility initiatives. Technically, the site is built on WordPress with modern web technologies including Google Tag Manager and a consent management platform, ensuring GDPR compliance and good SEO practices. Security posture is strong with HTTPS enforced and no evident vulnerabilities, though explicit security policies and incident response contacts are not published. Overall, the site demonstrates a mature digital presence with excellent content quality, user experience, and trustworthiness.

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

7 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';…

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

Keep watching o-seznam.cz

This scan found 24 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
95
Security headers
15
Email security
60
DNS health
70
Network security
100
GDPR outside view
25
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 o-seznam.cz, from OffSeq Breach.

No leaked records found

Breach holds no records for o-seznam.cz right now. New leaks arrive continuously, so monitoring on Breach alerts you if that changes.

Monitor on Breach (opens in a new tab)

Technical appendix

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

Business context

Business profile

Seznam.cz holds a dominant market position in the Czech Republic's internet sector, leveraging its extensive service offerings and proprietary infrastructure. Its business model focuses on providing a comprehensive internet platform for both consumers and businesses, including advertising solutions and media content. The company targets a wide audience ranging from general internet users to advertisers and publishers. The presence of certifications such as 'Agenturní spolupráce roku' and a large employee base indicate organizational maturity and market leadership. The company maintains active social media channels and invests in corporate social responsibility, enhancing its brand reputation. The website content and structure reflect a professional and consistent branding strategy aligned with its market stature.

Security posture

The website employs HTTPS with strong SSL configuration and integrates a consent management platform to comply with privacy regulations. Security best practices observed include the absence of exposed sensitive data and the use of modern tracking and advertising technologies with user consent. However, the site lacks explicit security policies, incident response contacts, and a vulnerability disclosure mechanism such as a security.txt file. No critical vulnerabilities or suspicious domains were detected. The security score is high but could be improved by publishing detailed security documentation and enhancing HTTP security headers. Overall, the security posture is robust for a corporate website but with room for transparency improvements.

Recommendations

  1. Publish a dedicated security policy page detailing security practices and compliance.
  2. Provide clear incident response contact channels such as security@ or abuse@ email addresses.
  3. Implement and publish a security.txt file to facilitate vulnerability disclosures.
  4. Enhance HTTP security headers including Content-Security-Policy, X-Frame-Options, and X-Content-Type-Options.
  5. Regularly audit third-party scripts and tracking technologies to ensure ongoing security and privacy compliance.

Contact details published on the site

Addresses
Legal name
Seznam.cz, a.s.
Site observations

Automated reading of the public site. Ratings are indicative.

Business

Company
Seznam.cz, a.s.
Description
Jsme česká internetová jednička se zálibou v technologiích a datech. Máme vlastní datová centra a provozujeme přes 30 služeb, o které se stará více než 1 900 Seznamáků. Jsme tak platformou nejen pro veřejnost, ale i podnikatele a vydavatele.
Key services
Vyhledávání, Reklama, Datová centra, IT služby, Marketing, Média
Content quality
excellent
Branding
consistent

Technology

Stack
Google Tag Manager, jQuery, Fancybox, WordPress
Frameworks
The SEO Framework
Platforms
WordPress
Performance
fast
Mobile
excellent
Accessibility
good
SEO
excellent

Security

Observed score
85/100
Good practices seen
  • HTTPS enforced
  • No exposed sensitive data in HTML
  • Use of Google Tag Manager with consent management platform
  • Consent Management Platform (CMP) scripts present

Analytics and tracking

Services
Google Analytics (via Google Tag Manager)
Tracking level
moderate
Privacy practices
good

Advertising

Ad networks
Seznam SSP
Marketing tools
Seznam SSP
Transparency
good

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 in Czech language
  2. Strong branding and consistent corporate identity
  3. Comprehensive career and corporate responsibility information
  4. Use of modern web technologies and SEO best practices
  5. Presence of consent management platform indicating GDPR compliance
  6. No direct contact emails or phone numbers found on main page; contact info limited to physical address
  7. No explicit security policy or incident response contacts published
  8. No security.txt or vulnerability disclosure page detected
Technical notes

Notes

The website is built on WordPress CMS using a modern and well-structured theme with The SEO Framework plugin for SEO optimization. It uses Google Tag Manager for analytics and marketing tags, jQuery for JavaScript functionality, and Fancybox for UI components. The site is mobile-optimized with responsive design and accessibility features such as skip links for screen readers. Performance is optimized with preloading fonts and asynchronous script loading. The technical implementation reflects a mature and professional web infrastructure suitable for a large enterprise. Hosting details are not explicitly disclosed but the presence of proprietary data centers is noted in the business description.
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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