CVE-2021-21818

Name: CVE-2021-21818
Creator: NVD / NIST
Published: 2021-07-16T11:15:09.97+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 1.95%

Last modified Jun 17, 2026

CVE-2021-21818 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. A hard-coded password vulnerability exists in the Zebra IP Routing Manager functionality of D-LINK DIR-3040 1.13B03. A specially crafted network request can lead to a denial of service. EPSS estimates a 1.95% chance of exploitation in the next 30 days.

Description

A hard-coded password vulnerability exists in the Zebra IP Routing Manager functionality of D-LINK DIR-3040 1.13B03. A specially crafted network request can lead to a denial of service. An attacker can send a sequence of requests to trigger this vulnerability.

Metrics

CVSS 3.1

7.5/10

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

EPSS Probability

1.95%

77.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Dlink	Dir-3040 Firmware	1.13b03

References

https://talosintelligence.com/vulnerability_reports/TALOS-2021-1283Exploit, Third Party Advisory
https://talosintelligence.com/vulnerability_reports/TALOS-2021-1283Exploit, Third Party Advisory

Timeline

Published: Jul 16, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-21818?

How severe is CVE-2021-21818?

CVE-2021-21818 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 1.95% probability of exploitation in the next 30 days.

How do I fix CVE-2021-21818?

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-2021-21818?

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

Scan your code now

Source: NVD / NIST