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Security report for zulip.com

Kandra Labs, Inc. · Technology · N/a

Low risk. 4 critical or high findings in Security headers, GDPR outside view and 1 other check.

Security score

79/100

Risk levelLow

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

Zulip, operated by Kandra Labs, Inc., is a mature technology company founded in 2010 that provides an organized team chat platform designed for distributed teams of all sizes. The company offers both cloud-hosted and self-hosted open-source chat solutions, targeting businesses, educational institutions, research groups, open source projects, and communities. Their market position is focused on asynchronous communication with strong open-source transparency and flexibility. The website features extensive case studies, testimonials, and a comprehensive product overview, reflecting a professional and trustworthy brand. Technically, the website employs a modern JavaScript stack with Webpack bundling, Google Analytics, Google Tag Manager, and Sentry for error tracking. Hosting is inferred to be on Amazon AWS based on DNS nameservers. The site is well-optimized for performance, mobile responsiveness, accessibility, and SEO, with a custom-built CMS or framework. The presence of deferred scripts and responsive images indicates good technical maturity. From a security perspective, the site enforces HTTPS and has domain transfer protections in place. However, DNSSEC is not enabled, and no explicit security headers were detected in the provided data. The company provides a dedicated security page but lacks a published vulnerability disclosure or security.txt file. Privacy compliance is partially addressed with a comprehensive privacy policy and terms of service, but no cookie consent mechanism was found. Contact information is available primarily via support forms rather than direct emails or phone numbers. Overall, Zulip demonstrates a strong business credibility and technical foundation with a good security posture, though improvements in DNS security and privacy consent mechanisms are recommended. The website content is safe for general audiences, professional, and well-structured, supporting a high trustworthiness rating.

Scanned

NIS2 and GDPR posture

GDPR outside view
65/ 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

4 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 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

  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 SSL Key Length

      SSL certificate uses 256-bit key, which is considered weak

      What to do: Use at least 2048-bit RSA or 256-bit ECC key

      • CWE-326
      • OWASP A04:2025
      • Mozilla TLS: Mozilla Server Side TLS 6.0 intermediate: rsa_key_size 2048

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

Keep watching zulip.com

This scan found 15 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

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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
80
Security headers
50
Email security
95
DNS health
85
Network security
100
GDPR outside view
65
Average
79

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

Zulip operates in the competitive team collaboration software market with a unique focus on asynchronous communication and open-source self-hosting options. Their business model includes SaaS cloud offerings and free self-hosted software, appealing to a broad range of customers from small businesses to large enterprises and educational institutions. The company leverages community engagement, detailed case studies, and open source transparency as competitive advantages. Revenue streams likely include paid cloud plans and enterprise demos. The partnership ecosystem includes integrations with various tools and an active development community. Growth indicators include recent blog posts and continuous product updates. Strategic observations highlight the importance of maintaining open-source leadership and expanding cloud adoption while enhancing security and privacy compliance.

Security posture

Zulip's security posture is solid with mandatory HTTPS, domain transfer lock, and open-source transparency allowing community scrutiny. The presence of a dedicated security page indicates awareness and commitment to security best practices. However, the absence of DNSSEC and explicit security headers suggests room for improvement. No vulnerabilities or exposed sensitive data were detected in the analysis. Privacy compliance is partial, lacking cookie consent mechanisms and vulnerability disclosure policies. Incident response contact channels are not explicitly published. Overall, the security maturity is good but could be enhanced by adopting DNSSEC, publishing a security.txt, and implementing cookie consent to meet GDPR fully.

Recommendations

  1. Enable DNSSEC on the domain to improve DNS security and prevent spoofing.
  2. Implement and display a cookie consent banner to comply with GDPR and other privacy regulations.
  3. Publish a vulnerability disclosure policy or security.txt file to facilitate responsible reporting.
  4. Add standard security headers such as Content-Security-Policy, Strict-Transport-Security, and X-Frame-Options.
  5. Consider providing direct security incident contact emails to improve incident response readiness.
Site observations

Automated reading of the public site. Ratings are indicative.

Business

Company
Kandra Labs, Inc.
Description
Zulip is an organized team chat app for distributed teams of all sizes.
Key services
Team chat application, Cloud-hosted chat service, Self-hosted open-source chat server, Integrations and API, Desktop and mobile apps
Content quality
excellent
Branding
consistent

Technology

Stack
JavaScript, Webpack, Google Analytics, Google Tag Manager, Sentry
Platforms
Web, Desktop apps, Mobile apps
Performance
fast
Mobile
excellent
Accessibility
good
SEO
good

Security

Observed score
85/100
Good practices seen
  • HTTPS enforced
  • Client transfer prohibited domain status
  • Open source software allowing transparency
  • Security page available

Analytics and tracking

Services
Google Analytics, Google Tag Manager, Sentry
Tracking level
moderate
Privacy practices
basic

Advertising

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 navigation.
  2. Strong focus on asynchronous team chat for distributed teams.
  3. Open source software emphasized for transparency and self-hosting.
  4. Multiple customer case studies and testimonials enhance trust.
  5. No explicit contact emails or phone numbers found; contact via support form.
  6. No cookie consent banner detected despite GDPR references.
  7. Modern JavaScript tech stack with deferred loading and CDN usage.
  8. No explicit security.txt or vulnerability disclosure page found.
  9. Social media presence on Twitter, Mastodon, LinkedIn.
  10. No suspicious or malicious content detected.
Technical notes

Notes

The website uses a modern JavaScript-based tech stack with Webpack for bundling and deferred script loading to optimize performance. Google Analytics and Tag Manager are used for analytics, and Sentry is employed for error monitoring. Hosting is likely on AWS, inferred from DNS nameservers. The site is mobile-optimized with responsive images and good accessibility features. No common CMS was detected, indicating a custom or proprietary solution. Performance is fast with good SEO metadata and Open Graph tags. Technical risks are minimal, but the lack of DNSSEC and some security headers represent moderate technical debt. Overall, the infrastructure is robust and well-maintained.
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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