# CVE-2021-34580

## Summary

- **CVE ID:** CVE-2021-34580
- **Severity:** HIGH
- **CVSS Score:** 7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N)
- **CWE:** CWE-204
- **Published:** Oct 27, 2021
- **Last Modified:** Mar 13, 2026

## Description

In mymbCONNECT24, mbCONNECT24 <= 2.9.0 an unauthenticated user can enumerate valid backend users by checking what kind of response the server sends for crafted invalid login attempts.

## Affected Products

- MB connect line — mymbCONNECT24 (2.9.0)
- MB connect line — mbCONNECT24 (2.9.0)

## References

- [CNA](https://cert.vde.com/en/advisories/VDE-2021-037/)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.27%
- **EPSS Percentile:** 50.5

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-18._