CVE-2021-43403 : Security Advisory and Response

An issue was discovered in FusionPBX before 4.5.30 where an authenticated user can download an arbitrary filename on the log_viewer.php Log View page.

Understanding CVE-2021-43403

This CVE involves a vulnerability in FusionPBX that allows authenticated users to download files with arbitrary filenames.

What is CVE-2021-43403?

The vulnerability in FusionPBX before version 4.5.30 enables authenticated users to select any file for download on the log_viewer.php Log View page, potentially leading to unauthorized access to sensitive files.

The Impact of CVE-2021-43403

The vulnerability could result in unauthorized retrieval and exposure of sensitive information within the affected FusionPBX system.

Technical Details of CVE-2021-43403

This section provides more in-depth technical information about the CVE.

Vulnerability Description

The issue allows authenticated users to choose any filename for download on the log_viewer.php Log View page, expanding beyond the intended file access restrictions.

Affected Systems and Versions

Product: FusionPBX
Versions affected: Before 4.5.30

Exploitation Mechanism

An authenticated user can exploit this vulnerability by manipulating the filename parameter in the download request, potentially accessing sensitive files.

Mitigation and Prevention

Protect your system against CVE-2021-43403 with the following actions.

Immediate Steps to Take

Upgrade FusionPBX to version 4.5.30 or newer to address the vulnerability.
Restrict access to the log_viewer.php page to authorized users only.

Long-Term Security Practices

Regularly review and update access controls to prevent unauthorized file downloads.
Educate users on safe file download practices to mitigate risks.

Patching and Updates

Apply security patches promptly to ensure system integrity and address known vulnerabilities.