CVE-2021-33527

Name: CVE-2021-33527
Creator: NVD / NIST
Published: 2021-08-02T11:15:11.287+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 4.52%

Last modified Jun 17, 2026

CVE-2021-33527 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. In MB connect line mbDIALUP versions <= 3.9R0.0 a remote attacker can send a specifically crafted HTTP request to the service running with NT AUTHORITY\SYSTEM that will not correctly validate the input. This can lead to an arbitrary code execution with the privileges of the service.. EPSS estimates a 4.52% chance of exploitation in the next 30 days.

Description

In MB connect line mbDIALUP versions <= 3.9R0.0 a remote attacker can send a specifically crafted HTTP request to the service running with NT AUTHORITY\SYSTEM that will not correctly validate the input. This can lead to an arbitrary code execution with the privileges of the service.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

4.52%

90.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Mbconnectline	Mbdialup	<= 3.9r0.0

References

https://cert.vde.com/de-de/advisories/vde-2021-017Third Party Advisory
https://cert.vde.com/de-de/advisories/vde-2021-017Third Party Advisory

Timeline

Published: Aug 2, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-33527?

How severe is CVE-2021-33527?

CVE-2021-33527 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 4.52% probability of exploitation in the next 30 days.

How do I fix CVE-2021-33527?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-33527?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST