What is CVE-2021-34861?

CVE-2021-34861 is a high-severity vulnerability in D-Link Dap-2020, classified under Stack-based Buffer Overflow. CVSS score: 8.8/10. Published 2021-10-25.

How severe is CVE-2021-34861?

High severity. CVSS v3 base score is 8.8 out of 10.

Is CVE-2021-34861 known to be exploited?

2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Buffer overflow in D-Link Dap-2020

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.

Vulnerability class: Buffer Overflow

EPSS: 0.008 (54.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

CWE-121 — Stack-based Buffer Overflow

Public proof-of-concept exploits

References

zdi-disclosures@trendmicro.com (Patch, x_refsource_MISC, Vendor Advisory)
zdi-disclosures@trendmicro.com (VDB Entry, Third Party Advisory, x_refsource_MISC)

Frequently asked questions

What is CVE-2021-34861?: CVE-2021-34861 is a high-severity vulnerability in D-Link Dap-2020, classified under Stack-based Buffer Overflow. CVSS score: 8.8/10. Published 2021-10-25.
How severe is CVE-2021-34861?: High severity. CVSS v3 base score is 8.8 out of 10.
Is CVE-2021-34861 known to be exploited?: 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.