CVE-2021-27692 : Vulnerability Insights and Analysis

A command injection vulnerability has been identified in Tenda G1 and G3 routers with specific firmware versions, allowing remote attackers to execute arbitrary OS commands. This vulnerability arises from the execution of untrusted input within the "formSetUSBPartitionUmount" function.

Understanding CVE-2021-27692

This section provides insights into the nature and impact of the CVE-2021-27692 vulnerability.

What is CVE-2021-27692?

CVE-2021-27692 is a command injection vulnerability present in Tenda G1 and G3 routers with specific firmware versions, facilitating the execution of unauthorized OS commands by attackers through a specially crafted request.

The Impact of CVE-2021-27692

The exploitation of this vulnerability can lead to severe consequences, allowing remote threat actors to execute arbitrary commands on affected routers, compromising the security and integrity of the network.

Technical Details of CVE-2021-27692

In this section, we delve into the technical aspects of CVE-2021-27692, including the vulnerability description, affected systems and versions, and exploitation mechanism.

Vulnerability Description

The vulnerability in Tenda routers arises from inadequate input validation in the "formSetUSBPartitionUmount" function, enabling malicious actors to execute unauthorized OS commands.

Affected Systems and Versions

CVE-2021-27692 impacts Tenda G1 and G3 routers specifically with firmware versions v15.11.0.17(9502)_CN or v15.11.0.16(9024)_CN.

Exploitation Mechanism

Remote attackers exploit CVE-2021-27692 by sending a specially crafted "action/umountUSBPartition" request to the affected routers, leveraging the vulnerable "doSystemCmd" function to execute unauthorized commands.

Mitigation and Prevention

This section covers essential steps to mitigate the risks posed by CVE-2021-27692 and prevent potential exploitation.

Immediate Steps to Take

Update the firmware of Tenda G1 and G3 routers to the latest version that addresses the command injection vulnerability.
Restrict network access to the routers and implement strict firewall rules to minimize attack surface.

Long-Term Security Practices

Regularly monitor for firmware updates and security advisories from Tenda to stay informed about potential vulnerabilities.
Conduct security assessments and penetration testing to identify and address any security gaps in the network infrastructure.

Patching and Updates

It is crucial to promptly apply security patches released by Tenda for the affected routers to eliminate the command injection vulnerability and enhance overall network security.