CVE-2021-40845 : What You Need to Know

Zenitel AlphaCom XE Audio Server through 11.2.3.10 is susceptible to arbitrary PHP code execution through a file upload vulnerability in AlphaWeb XE.

Understanding CVE-2021-40845

AlphaWeb XE in Zenitel AlphaCom XE Audio Server allows the upload of files in the Custom Scripts section without proper validation, enabling PHP code execution.

What is CVE-2021-40845?

The vulnerability in Zenitel AlphaCom XE Audio Server up to version 11.2.3.10 permits the unrestricted file upload of PHP files, facilitating the execution of malicious code within the /cmd directory.

The Impact of CVE-2021-40845

This vulnerability could result in the execution of arbitrary PHP code by an attacker, leading to system compromise, data loss, or unauthorized access to sensitive information.

Technical Details of CVE-2021-40845

Zenitel AlphaCom XE Audio Server's vulnerability can be further understood through the following details:

Vulnerability Description

The issue arises from the lack of proper file upload restrictions in the AlphaWeb XE component, allowing PHP file uploads and subsequent execution in the /cmd directory.

Affected Systems and Versions

Zenitel AlphaCom XE Audio Server through 11.2.3.10

Exploitation Mechanism

The vulnerability can be exploited by uploading a specially crafted PHP file through the Custom Scripts section in AlphaWeb XE, triggering the execution of malicious code.

Mitigation and Prevention

To address and prevent CVE-2021-40845:

Immediate Steps to Take

Disable file uploads in the Custom Scripts section if not essential
Implement content and extension validation for uploaded files
Monitor the /cmd directory for any unauthorized PHP scripts

Long-Term Security Practices

Regularly update and patch Zenitel AlphaCom XE Audio Server
Conduct security assessments and audits to detect similar vulnerabilities

Patching and Updates

Zenitel may release patches or updates to address the file upload vulnerability in the AlphaWeb XE component.