How severe is CVE-2021-21817?

CVE-2021-21817 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2021-21817 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (79th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-21817?

CVE-2021-21817 affects Dlink Dir-3040 Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-21817?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-21817 published?

CVE-2021-21817 was published on 2021-07-16 and last updated on 2026-06-17.

CVE-2021-21817

CVE-2021-21817 is a high-severity vulnerability in Dlink Dir-3040 Firmware with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-200.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 2% (79th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-200
Affected product: Dlink Dir-3040 Firmware
Published: 2021-07-16
Last modified: 2026-06-17

Description

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

Frequently asked questions

What is CVE-2021-21817?: An information disclosure vulnerability exists in the Zebra IP Routing Manager functionality of D-LINK DIR-3040 1.13B03. A specially crafted network request can lead to the disclosure of sensitive information. An attacker can send a sequence of requests to trigger this vulnerability.
How severe is CVE-2021-21817?: CVE-2021-21817 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2021-21817 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (79th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-21817?: CVE-2021-21817 affects Dlink Dir-3040 Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-21817?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-21817 published?: CVE-2021-21817 was published on 2021-07-16 and last updated on 2026-06-17.

References

https://talosintelligence.com/vulnerability_reports/TALOS-2021-1282

Affected products (1)

cpe:2.3:o:dlink:dir-3040_firmware:1.13b03:*:*:*:*:*:*:*

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