CVE-2021-25309

Name: CVE-2021-25309
Creator: NVD / NIST
Published: 2021-03-02T01:15:12.697+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 1.35%

Last modified Jun 17, 2026

CVE-2021-25309 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. The telnet administrator service running on port 650 on Gigaset DX600A v41.00-175 devices does not implement any lockout or throttling functionality. This situation (together with the weak password policy that forces a 4-digit password) allows remote attackers to easily obtain administrative access via brute-force attacks.. EPSS estimates a 1.35% chance of exploitation in the next 30 days.

Description

The telnet administrator service running on port 650 on Gigaset DX600A v41.00-175 devices does not implement any lockout or throttling functionality. This situation (together with the weak password policy that forces a 4-digit password) allows remote attackers to easily obtain administrative access via brute-force attacks.

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

1.35%

67.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Gigaset	Dx600a Firmware	v41.00-175

References

Timeline

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

Frequently Asked Questions

What is CVE-2021-25309?

How severe is CVE-2021-25309?

CVE-2021-25309 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 1.35% probability of exploitation in the next 30 days.

How do I fix CVE-2021-25309?

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-2021-25309?

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

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Source: NVD / NIST