CVE-2021-27246 Explained : Impact and Mitigation

A vulnerability in TP-Link Archer A7 AC1750 routers allows attackers to execute arbitrary code without authentication, posing a critical security risk.

Understanding CVE-2021-27246

This CVE-2021-27246 vulnerability affects TP-Link Archer A7 AC1750 routers, enabling network-adjacent attackers to execute code without authentication.

What is CVE-2021-27246?

CVE-2021-27246 is a critical vulnerability that permits attackers to run arbitrary code on affected TP-Link Archer A7 AC1750 routers. The flaw is related to the mishandling of MAC addresses by the tdpServer endpoint.

The Impact of CVE-2021-27246

The impact of this vulnerability is severe, as attackers can exploit it to execute code in the context of the root user without needing any privileges. This could lead to unauthorized access and potential attacks.

Technical Details of CVE-2021-27246

This section delves into the technical aspects of the CVE-2021-27246 vulnerability.

Vulnerability Description

The vulnerability arises from a stack-based buffer overflow (CWE-121) in the handling of MAC addresses by the tdpServer endpoint on TP-Link Archer A7 AC1750 routers.

Affected Systems and Versions

TP-Link Archer A7 AC1750 routers running version 1.0.15 Build 20200628 rel.63501(4341) are impacted by CVE-2021-27246.

Exploitation Mechanism

By sending a crafted TCP message, attackers can write stack pointers to the stack, allowing them to execute code as the root user.

Mitigation and Prevention

Protecting your systems from CVE-2021-27246 requires immediate action and long-term security measures.

Immediate Steps to Take

Update TP-Link Archer A7 AC1750 routers to the latest firmware version to patch the vulnerability.
Monitor network traffic for any suspicious activities.

Long-Term Security Practices

Regularly update all network devices to mitigate potential security risks.
Implement network segmentation to limit the impact of future vulnerabilities.

Patching and Updates

Stay informed about security advisories from TP-Link and apply patches promptly to ensure the protection of your network.