CVE-2021-21895 : What You Need to Know

A directory traversal vulnerability exists in the Web Manager FsTFtp functionality of Lantronix PremierWave 2050 8.9.0.0R4 (in QEMU). This vulnerability allows an attacker to overwrite FsTFtp files by sending a specially crafted HTTP request.

Understanding CVE-2021-21895

This section will delve into the details of the CVE-2021-21895 vulnerability.

What is CVE-2021-21895?

CVE-2021-21895 is a directory traversal vulnerability found in the Web Manager FsTFtp functionality of Lantronix PremierWave 2050 8.9.0.0R4 (in QEMU). Attackers can exploit this vulnerability through authenticated HTTP requests to overwrite files.

The Impact of CVE-2021-21895

With a CVSS base score of 9.1 (Critical severity), this vulnerability poses a significant threat. The availability, confidentiality, and integrity of the affected system are all at high risk. The attack vector involves network access with high privileges required, making the impact severe.

Technical Details of CVE-2021-21895

Let's explore the technical aspects of CVE-2021-21895 in more depth.

Vulnerability Description

The vulnerability arises from improper pathname limitation in the Web Manager FsTFtp feature of Lantronix PremierWave 2050 8.9.0.0R4. This allows malicious actors to overwrite files via HTTP requests.

Affected Systems and Versions

The specific version impacted by this vulnerability is Lantronix PremierWave 2050 8.9.0.0R4 running in QEMU.

Exploitation Mechanism

Attackers can exploit this vulnerability by sending specially crafted HTTP requests to the targeted system, triggering the directory traversal issue.

Mitigation and Prevention

To safeguard your systems from CVE-2021-21895, consider the following mitigation strategies.

Immediate Steps to Take

Apply patches or updates provided by Lantronix to fix the directory traversal vulnerability.
Monitor network traffic for any suspicious HTTP requests that could indicate an exploitation attempt.

Long-Term Security Practices

Implement network segmentation to limit access to critical systems.
Conduct regular security assessments to identify and address any potential vulnerabilities.

Patching and Updates

Stay informed about security advisories from Lantronix and promptly apply patches to eliminate known vulnerabilities.