CVE-2021-20134 : Exploit Details and Defense Strategies

A detailed analysis of CVE-2021-20134 focusing on an absolute path traversal vulnerability in Quagga Services on D-Link DIR-2640 Routers.

Understanding CVE-2021-20134

This section provides insights into the critical vulnerability affecting certain versions of Quagga Services on D-Link DIR-2640 Routers.

What is CVE-2021-20134?

The CVE-2021-20134 vulnerability involves an absolute path traversal issue that impacts Quagga Services on D-Link DIR-2640 Routers with versions equal to or less than 1.11B02. This flaw allows a remote attacker to manipulate log files and potentially execute arbitrary code on the device.

The Impact of CVE-2021-20134

An attacker, even with remote, unauthenticated access, can exploit this vulnerability to write files to the device's filesystem and trigger remote code execution. By infiltrating the log file system, the attacker can gain root access to the router.

Technical Details of CVE-2021-20134

This section delves into the specifics of the vulnerability and its potential ramifications.

Vulnerability Description

The vulnerability allows remote, authenticated attackers to manipulate log files on the router's filesystem, potentially leading to remote code execution and the acquisition of a root shell on the device.

Affected Systems and Versions

Quagga Services running on D-Link DIR-2640 Routers with versions equal to or less than 1.11B02 are susceptible to this security flaw.

Exploitation Mechanism

Attackers can exploit the absolute path traversal vulnerability by setting arbitrary files as log files, enabling the execution of malicious scripts and granting unauthorized access.

Mitigation and Prevention

This section outlines steps to mitigate the risks posed by CVE-2021-20134 and secure affected systems.

Immediate Steps to Take

Users should update Quagga Services on D-Link DIR-2640 Routers to versions beyond 1.11B02 to prevent exploitation of the absolute path traversal vulnerability. Network segmentation and access control are also recommended.

Long-Term Security Practices

Maintaining regular software updates, implementing intrusion detection systems, and conducting security audits can help fortify the network against cyber threats.

Patching and Updates

Stay informed about security advisories and promptly apply patches released by Quagga Services and D-Link to address CVE-2021-20134 and other potential vulnerabilities.