CVE-2021-21879 : Exploit Details and Defense Strategies

A directory traversal vulnerability in Lantronix PremierWave 2050 8.9.0.0R4 allows attackers to overwrite files via specially-crafted HTTP requests.

Understanding CVE-2021-21879

This CVE involves a critical directory traversal vulnerability in Lantronix PremierWave 2050 8.9.0.0R4, impacting file upload functionality.

What is CVE-2021-21879?

The CVE describes a flaw in Lantronix's PremierWave 2050 that could be exploited by an authenticated attacker to overwrite arbitrary files using a crafted HTTP request.

The Impact of CVE-2021-21879

With a CVSS base score of 9.9(out of 10), this critical vulnerability can lead to high confidentiality, integrity, and availability impacts on affected systems.

Technical Details of CVE-2021-21879

This section covers specific technical aspects of the CVE.

Vulnerability Description

The vulnerability allows remote attackers to perform directory traversal attacks, leading to arbitrary file overwrite.

Affected Systems and Versions

Lantronix PremierWave 2050 version 8.9.0.0R4 running in QEMU is affected by this vulnerability.

Exploitation Mechanism

Exploitation involves sending a specially-crafted HTTP request to the Web Manager File Upload functionality to trigger the arbitrary file overwrite.

Mitigation and Prevention

Effective mitigation strategies to protect systems from CVE-2021-21879.

Immediate Steps to Take

Disable or restrict access to the Web Manager File Upload functionality. Monitor network traffic for any suspicious activities.

Long-Term Security Practices

Regularly update Lantronix PremierWave 2050 firmware versions to ensure the latest security patches are applied.

Patching and Updates

Apply security patches released by Lantronix to fix the directory traversal vulnerability and prevent potential exploitation.