CVE-2021-34861: D-Link DAP-2020 webproc Stack-based Buffer Overflow Remote Code Execution Vulnerability

Published Oct 25, 2021
·
Updated

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.

Other sources

This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of D-Link DAP-2020 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.

ZDI

Affected Software

3 affected components
Dlink Dap-2020 Firmware<=1.01
Dlink Dap-2020
D-Link DAP-2020

Event History

Oct 25, 2021
CVE Published
via MITRE·05:10 PM
Data Sourced
via MITRE·05:10 PM
DescriptionSeverityWeakness
Feb 28, 2025
Advisory Published
via ZDI·12:15 PM
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Frequently Asked Questions

1

What is the vulnerability ID for this D-Link DAP-2020 vulnerability?

The vulnerability ID for this D-Link DAP-2020 vulnerability is CVE-2021-34861.

2

How severe is CVE-2021-34861?

CVE-2021-34861 has a severity rating of 8.8 out of 10 (high).

3

What is the affected software for CVE-2021-34861?

The affected software for CVE-2021-34861 is D-Link DAP-2020 firmware version up to and including 1.01.

4

How can an attacker exploit CVE-2021-34861?

An attacker can exploit CVE-2021-34861 by sending specially crafted requests to the webproc endpoint on TCP port 80 of the affected D-Link DAP-2020 router.

5

Is authentication required to exploit CVE-2021-34861?

No, authentication is not required to exploit CVE-2021-34861.

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