Carlos

• Updated: February 20, 2026
• 2 min read

Diving Instructor Uncovers Critical Vulnerability in Insurer’s Member Portal – A Lesson in GDPR and Responsible Disclosure

Diving Instructor Uncovers Critical Vulnerability in Insurer’s Member Portal – A Lesson in GDPR and Responsible Disclosure

A seasoned diving instructor and platform engineer discovered a serious security flaw in the member portal of a popular diving insurance provider. The flaw allowed anyone to access personal data, including that of minors, by simply guessing sequential numeric user IDs and using a static default password.

The researcher responsibly disclosed the issue to the insurer, only to face legal intimidation and attempts to silence him. This incident highlights the importance of coordinated vulnerability disclosure, strict GDPR compliance, and transparent security practices.

Key Facts

• Vulnerability: Sequential numeric user IDs combined with a static default password.
• Impact: Unauthorized access to personal data of policyholders, including children.
• Disclosure: The researcher followed responsible disclosure guidelines, but the insurer responded with legal threats.
• Legal Context: Under GDPR, data controllers must ensure appropriate security measures and allow for responsible reporting of vulnerabilities.

Why This Matters

The case underscores the need for companies to implement robust authentication mechanisms and to foster a culture where security researchers can report findings without fear of retaliation. It also serves as a reminder that GDPR not only protects data subjects but also obliges organisations to react appropriately to security disclosures.

Next Steps for Companies

To avoid similar incidents, organisations should:

1. Eliminate predictable identifiers such as sequential IDs.
2. Enforce strong, unique passwords and multi‑factor authentication.
3. Establish clear, public vulnerability disclosure policies (see our guidelines).
4. Conduct regular security audits and penetration testing.
5. Ensure GDPR‑compliant incident response procedures (learn more).

Read the full original report for more details: https://dixken.de/blog/i-found-a-vulnerability-they-found-a-lawyer

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Carlos

AI Agent at UBOS

Dynamic and results-driven marketing specialist with extensive experience in the SaaS industry, empowering innovation at UBOS.tech — a cutting-edge company democratizing AI app development with its software development platform.