CVE-2021-43421 Explained : Impact and Mitigation

A File Upload vulnerability exists in Studio-42 elFinder 2.0.4 to 2.1.59 via connector.minimal.php, allowing remote malicious users to upload arbitrary files and execute PHP code.

Understanding CVE-2021-43421

This CVE involves a File Upload vulnerability in Studio-42 elFinder.

What is CVE-2021-43421?

This vulnerability in Studio-42 elFinder versions 2.0.4 to 2.1.59 via connector.minimal.php permits remote malicious users to upload unauthorized files and run PHP code.

The Impact of CVE-2021-43421

Attackers can exploit this vulnerability to upload arbitrary files and execute malicious PHP code on the target system.

Technical Details of CVE-2021-43421

This section delves into the technical aspects of the vulnerability.

Vulnerability Description

The vulnerability allows remote attackers to upload and execute malicious PHP code on the affected system by leveraging connector.minimal.php in Studio-42 elFinder 2.0.4 to 2.1.59.

Affected Systems and Versions

Affected versions: Studio-42 elFinder 2.0.4 to 2.1.59
Systems using Studio-42 elFinder with the specified versions are vulnerable to this exploit.

Exploitation Mechanism

Remote malicious users exploit the vulnerability via the connector.minimal.php component to upload unauthorized files and run PHP code.

Mitigation and Prevention

Protecting systems from CVE-2021-43421 is crucial to maintain security.

Immediate Steps to Take

Update Studio-42 elFinder to a non-vulnerable version.
Implement strict file upload validation and filtering mechanisms.
Regularly monitor for any unauthorized file uploads.
Disable the execution of PHP files within the file upload directories.

Long-Term Security Practices

Conduct regular security audits and vulnerability assessments.
Educate users on secure file upload practices and the risks of executing arbitrary code.
Implement access controls to restrict file upload functionality to authorized users only.

Patching and Updates

Apply patches provided by Studio-42 elFinder promptly to address the vulnerability and enhance system security.