CVE-2021-39136 Explained : Impact and Mitigation

baserCMS is an open-source content management system with a focus on Japanese language support. In affected versions, there is a cross-site scripting vulnerability in the file upload function of the management system of baserCMS. Users are advised to update to version 4.5.1 or later to mitigate this issue.

Understanding CVE-2021-39136

This section provides insights into the cross-site scripting vulnerability in baserCMS.

What is CVE-2021-39136?

CVE-2021-39136 refers to a cross-site scripting vulnerability in baserCMS's file upload function. This vulnerability impacts versions prior to 4.5.1.

The Impact of CVE-2021-39136

The vulnerability has the following impacts:

Confidentiality Impact: High
Integrity Impact: High
Availability Impact: None
Base Score: 8.7 (High)
Attack Complexity: Low
Attack Vector: Network
User Interaction: Required

Technical Details of CVE-2021-39136

In this section, we delve into the technical aspects of the vulnerability.

Vulnerability Description

The vulnerability involves improper neutralization of input during web page generation, leading to cross-site scripting (CWE-79).

Affected Systems and Versions

Affected Product: baserCMS
Vendor: baserproject
Vulnerable Versions: < 4.5.1

Exploitation Mechanism

Attack Complexity: Low
Privileges Required: Low
Scope: Changed

Mitigation and Prevention

Learn how to protect your system from CVE-2021-39136.

Immediate Steps to Take

Update baserCMS to version 4.5.1 or later.

Long-Term Security Practices

Regularly monitor and patch vulnerabilities in your CMS.
Educate users on safe file uploading practices.

Patching and Updates

Regularly check for security advisories and updates from the baserCMS project.