CVE-2021-34863 Memory corruption in DAP-2020

High 8.8 Published 25 Oct 2021 Updated 4 Aug 2024

Network-adjacent attackers can execute arbitrary code as root on D-Link DAP-2020 routers via a stack buffer overflow in the webproc endpoint.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Local or same network only
Victim action needed: Not needed
Fix: None listed

What is CVE-2021-34863?

CVE-2021-34863 is a high-severity memory corruption vulnerability in D-Link DAP-2020, published on 25 Oct 2021. It can only be exploited from the same machine or local network, with no action from the victim.

Official 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 handling of the var:page parameter provided to the webproc endpoint. 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-13271.

Weakness: CWE-121

Which versions are affected by CVE-2021-34863?

It affects 1 product.

Products include Dlink Dap-2020 Firmware.

How do I fix CVE-2021-34863?

No fix has been published for CVE-2021-34863 yet. Limit exposure of the affected software until one is available.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2021-34863 being exploited?

There is no known exploitation of CVE-2021-34863 in the wild and no public exploit code.

Sources

Also known as GHSA-8v93-c335-x4h3.