CVE-2021-33903

Name: CVE-2021-33903
Creator: NVD / NIST
Published: 2021-10-07T15:15:10.593+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.8/10EPSS 1.07%

Last modified Jun 17, 2026

CVE-2021-33903 is a high-severity vulnerability rated 8.8/10 on the CVSS scale. In LCOS 10.40 to 10.42.0473-RU3 with SNMPv3 enabled on LANCOM devices, changing the password of the root user via the CLI does not change the password of the root user for SNMPv3 access. (However, changing the password of the root user via LANconfig does change the password of the root user for SNMPv3 access.). EPSS estimates a 1.07% chance of exploitation in the next 30 days.

Description

In LCOS 10.40 to 10.42.0473-RU3 with SNMPv3 enabled on LANCOM devices, changing the password of the root user via the CLI does not change the password of the root user for SNMPv3 access. (However, changing the password of the root user via LANconfig does change the password of the root user for SNMPv3 access.)

Metrics

CVSS 3.1

8.8/10

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

EPSS Probability

1.07%

60.5th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Vendor	Product	Versions
Lancom-Systems	Lcos	>= 10.40, < 10.42.0473
Lancom-Systems	Lcos	10.42.0473

References

https://www.nmedv.de/wp-content/uploads/2021/10/NME-2021-001.txtThird Party Advisory
https://www.nmedv.de/wp-content/uploads/2021/10/NME-2021-001.txtThird Party Advisory

Timeline

Published: Oct 7, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-33903?

How severe is CVE-2021-33903?

CVE-2021-33903 has a CVSS score of 8.8/10 (HIGH severity). The EPSS model estimates a 1.07% probability of exploitation in the next 30 days.

How do I fix CVE-2021-33903?

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-2021-33903?

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

Scan your code now

Source: NVD / NIST