CVE-2021-35003 : Security Advisory and Response

This vulnerability allows remote attackers to execute arbitrary code on affected installations of TP-Link Archer C90 routers without requiring authentication. The flaw is related to the handling of DNS responses, leading to a stack-based buffer overflow. Attackers can exploit this to execute code with root privileges.

Understanding CVE-2021-35003

This CVE refers to a critical vulnerability in TP-Link Archer C90 routers that enables attackers to remotely run arbitrary code without authentication, posing a severe security risk.

What is CVE-2021-35003?

CVE-2021-35003 allows malicious actors to trigger a stack-based buffer overflow through crafted DNS messages on TP-Link Archer C90 routers, enabling unauthorized code execution with root-level access.

The Impact of CVE-2021-35003

With a CVSS base score of 9.8 (Critical), this vulnerability has a high impact on confidentiality, integrity, and availability, as attackers can exploit it remotely without user interaction, resulting in severe consequences for affected systems.

Technical Details of CVE-2021-35003

This section provides insight into the technical aspects of CVE-2021-35003, including the vulnerability description, affected systems, and the exploitation mechanism.

Vulnerability Description

CVE-2021-35003 is classified as a stack-based buffer overflow vulnerability, allowing remote threat actors to abuse the DNS response handling in TP-Link Archer C90 routers to execute arbitrary code with elevated privileges.

Affected Systems and Versions

The vulnerability impacts TP-Link Archer C90 routers running version 1.0.6 Build 20200114 rel.73164(5553).

Exploitation Mechanism

Exploiting CVE-2021-35003 involves sending a maliciously crafted DNS message to trigger a stack-based buffer overflow, enabling attackers to execute arbitrary code on the targeted router with root privileges.

Mitigation and Prevention

To mitigate the risks associated with CVE-2021-35003, immediate steps must be taken to secure affected systems and implement long-term security practices.

Immediate Steps to Take

Disable remote access if not required.
Apply security patches and updates provided by TP-Link promptly.

Long-Term Security Practices

Regularly update firmware and software to address security vulnerabilities.
Monitor network traffic and DNS requests for any suspicious activities.

Patching and Updates

Ensure that the firmware of TP-Link Archer C90 routers is up to date to patch the CVE-2021-35003 vulnerability and protect the network from potential exploitation.