Overview
The world of cybersecurity is always on the move, with vulnerabilities cropping up regularly. Recently, a significant security flaw-CVE-2021-4457-has been identified in the ZoomSounds WordPress plugin. This vulnerability is particularly concerning as it can lead to potential system compromise or data leakage. Given the popularity of WordPress and the widespread use of plugins, this vulnerability has a broad impact surface and poses a serious risk to a large number of websites.
ZoomSounds, a widely-used audio player plugin, is used by countless websites to add multimedia features. However, versions of the plugin prior to 6.05 contain a critical flaw that allows unauthenticated users to upload arbitrary files anywhere on the web server, thus putting the integrity, confidentiality, and availability of the data at risk.
Vulnerability Summary
CVE ID: CVE-2021-4457
Severity: Critical (9.1 CVSS score)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: Potential system compromise or data leakage
Affected Products
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Product | Affected Versions
ZoomSounds Plugin | Before 6.05
How the Exploit Works
The vulnerability lies in the implementation of the ZoomSounds plugin, which contains a PHP file that does not properly validate user input. This allows unauthenticated users to upload arbitrary files to any location on the webserver. The uploaded file could contain malicious code, which, when executed, grants the attacker control over the system.
Conceptual Example Code
Below is a
conceptual
example of how the vulnerability might be exploited. This is a sample HTTP POST request demonstrating how a malicious user could upload an arbitrary file:
POST /zoomsounds-upload/endpoint.php HTTP/1.1
Host: vulnerable-website.com
Content-Type: multipart/form-data; boundary=----WebKitFormBoundary7MA4YWxkTrZu0gW
----WebKitFormBoundary7MA4YWxkTrZu0gW
Content-Disposition: form-data; name="file"; filename="malicious.php"
Content-Type: application/x-php
<?php
// malicious code
?>
----WebKitFormBoundary7MA4YWxkTrZu0gWAfter the malicious file is uploaded, the attacker can then access this file via a web browser to execute the malicious code.
Mitigation Guidance
To mitigate this vulnerability, users of the ZoomSounds plugin should immediately update to the latest version (6.05 or later), which contains a fix for this issue. If updating is not immediately possible, employing a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can provide temporary mitigation by blocking or alerting on attempts to exploit this vulnerability.