CVE-2020-8821 Explained : Impact and Mitigation

Webmin 1.941 and earlier versions contain an Improper Data Validation Vulnerability in the Command Shell Endpoint, allowing users to input HTML code into the Command field. When viewing logs in the Action Logs Menu, the HTML code is displayed without executing JavaScript.

Understanding CVE-2020-8821

This CVE involves an improper data validation issue in Webmin versions 1.941 and earlier, impacting the Command Shell Endpoint.

What is CVE-2020-8821?

An Improper Data Validation Vulnerability in Webmin 1.941 and earlier versions
Users can input HTML code in the Command field, which is rendered in the Action Logs Menu
JavaScript is not executed, but changes are maintained across users

The Impact of CVE-2020-8821

This vulnerability could be exploited by malicious users to inject malicious HTML code, potentially leading to various security risks.

Technical Details of CVE-2020-8821

Webmin 1.941 and earlier versions are affected by this vulnerability.

Vulnerability Description

Type: Improper Data Validation
Affected Component: Command Shell Endpoint
Risk: Allows injection of HTML code

Affected Systems and Versions

Webmin 1.941 and earlier

Exploitation Mechanism

User input of HTML code in the Command field
Viewing logs in the Action Logs Menu
HTML code is displayed without JavaScript execution

Mitigation and Prevention

It is crucial to take immediate steps to address and prevent exploitation of this vulnerability.

Immediate Steps to Take

Update Webmin to the latest version
Avoid inputting HTML code in untrusted fields
Monitor system logs for any suspicious activities

Long-Term Security Practices

Regularly update and patch Webmin and other software
Educate users on safe data input practices

Patching and Updates

Apply patches provided by Webmin to fix the vulnerability