# Hamburger Verkehrsverbund GmbH (HVV GmbH): Insufficient fulfilment of data breach notification obligations

- Type: Enforcement
- Source: Data Protection Authority of Hamburg
- Date: 2019-01-01
- Original: https://www.enforcementtracker.com/ETid-204
- Canonical: https://overview.legal/posts/46319
- Topics: Notification Obligation, Data Breaches, Article 19 GDPR - Notification of Rectification, Erasure or Restriction, Notified Body Reporting and Notification Obligations, IP Address, Security, Law Enforcement, Supervisory Authorities, Human Resources

## Summary

On July 6, 2018, HVV GmbH was informed by a customer about a security gap on the website www.hvv.de, which was caused by an update on February 5, 2018 and concerned the so-called Customer E-Service (CES). The security gap consisted in the fact that customers logged in to the CES who had an HVV Card and linked their CES customer account to at least one active contractual relationship in background systems could, by changing the URL, display data of other customers who had an HVV Card. This data b

## Full text

On July 6, 2018, HVV GmbH was informed by a customer about a security gap on the website www.hvv.de, which was caused by an update on February 5, 2018 and concerned the so-called Customer E-Service (CES). The security gap consisted in the fact that customers logged in to the CES who had an HVV Card and linked their CES customer account to at least one active contractual relationship in background systems could, by changing the URL, display data of other customers who had an HVV Card. This data breach was not reported to the data protection authority in a timely manner.

GDPR Articles: Art. 33 GDPR, Art. 34 GDPR
Industry: Transportation and Energy

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