How severe is CVE-2021-34861?

CVE-2021-34861 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-34861 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-34861?

CVE-2021-34861 affects Dlink Dap-2020 Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-34861?

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-2021-34861 published?

CVE-2021-34861 was published on 2021-10-25 and last updated on 2026-06-17.

CVE-2021-34861

CVE-2021-34861 is a high-severity vulnerability in Dlink Dap-2020 Firmware with a CVSS 3.x base score of 8.8. 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-121.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 5.8
EPSS exploit prediction: 1% (52nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-121
Affected product: Dlink Dap-2020 Firmware
Published: 2021-10-25
Last modified: 2026-06-17

Description

This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of D-Link DAP-2020 1.01rc001 routers. Authentication is not required to exploit this vulnerability. The specific flaw exists within the webproc endpoint, which listens on TCP port 80 by default. The issue results from the lack of proper validation of the length of user-supplied data prior to copying it to a fixed-length stack-based buffer. An attacker can leverage this vulnerability to execute code in the context of root. Was ZDI-CAN-12104.

Frequently asked questions

What is CVE-2021-34861?: This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of D-Link DAP-2020 1.01rc001 routers. Authentication is not required to exploit this vulnerability. The specific flaw exists within the webproc endpoint, which listens on TCP port 80 by default. The issue results from the lack of proper validation of the length of user-supplied data prior to copying it to a fixed-length stack-based buffer. An attacker can leverage this vulnerability to execute code in the context of root. Was ZDI-CAN-12104.
How severe is CVE-2021-34861?: CVE-2021-34861 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-34861 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-34861?: CVE-2021-34861 affects Dlink Dap-2020 Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-34861?: 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-2021-34861 published?: CVE-2021-34861 was published on 2021-10-25 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:dlink:dap-2020_firmware:*:*:*:*:*:*:*:*

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