CVE-2021-34863 : Security Advisory and Response

This article provides detailed information about CVE-2021-34863, a vulnerability that allows network-adjacent attackers to execute arbitrary code on D-Link DAP-2020 1.01rc001 routers without authentication.

Understanding CVE-2021-34863

This section will cover the impact, technical details, and mitigation strategies related to CVE-2021-34863.

What is CVE-2021-34863?

CVE-2021-34863 is a vulnerability in D-Link DAP-2020 1.01rc001 routers that enables attackers to execute code without the need for authentication. The flaw lies in the improper handling of user-supplied data, leading to a stack-based buffer overflow.

The Impact of CVE-2021-34863

The impact of this vulnerability is rated as high, with the potential for an attacker to execute arbitrary code in the context of root. Attackers can exploit this issue with a low attack complexity and without requiring any privileges.

Technical Details of CVE-2021-34863

This section dives deeper into the vulnerability description, affected systems and versions, as well as the exploitation mechanism.

Vulnerability Description

The vulnerability is due to inadequate data validation in the var:page parameter passed to the webproc endpoint. This lack of validation allows attackers to overflow a fixed-length stack buffer.

Affected Systems and Versions

D-Link DAP-2020 routers running version 1.01rc001 are affected by this vulnerability. Users of this specific version should take immediate action to mitigate the risk.

Exploitation Mechanism

Attackers can exploit this vulnerability by providing specially crafted data to the var:page parameter, triggering the buffer overflow and gaining the ability to run arbitrary code.

Mitigation and Prevention

This section outlines the steps to take immediately, as well as long-term security practices and the importance of patching and updates.

Immediate Steps to Take

Users of D-Link DAP-2020 1.01rc001 routers should update their firmware to the latest version provided by the vendor. Implementing network segmentation and access controls can also reduce the risk of exploitation.

Long-Term Security Practices

To enhance security, it is recommended to regularly monitor for security advisories, conduct security assessments, and follow best practices for secure coding and configuration.

Patching and Updates

Keep systems up to date with the latest security patches and firmware releases from D-Link. Regularly check for new updates and apply them promptly to protect against known vulnerabilities.