CVE-2026-28502: WWBN AVideo Plugin Upload RCE Vulnerability

CVE-2026-28502 Overview

WWBN AVideo is an open source video platform that prior to version 24.0 contained an authenticated Remote Code Execution (RCE) vulnerability in the plugin upload/import functionality. The vulnerability allows an authenticated administrator to upload a specially crafted ZIP archive containing executable server-side files. Due to insufficient validation of extracted file contents, the archive is extracted directly into a web-accessible plugin directory, enabling arbitrary PHP code execution on the target server.

Critical Impact

This vulnerability allows authenticated administrators to achieve arbitrary code execution on the server through malicious plugin uploads, potentially leading to complete server compromise, data theft, and lateral movement within the network.

Affected Products

• WWBN AVideo versions prior to 24.0
• AVideo plugin upload/import functionality
• Self-hosted AVideo installations with administrative access

Discovery Timeline

• 2026-03-06 - CVE-2026-28502 published to NVD
• 2026-03-09 - Last updated in NVD database

Technical Details for CVE-2026-28502

Vulnerability Analysis

This vulnerability is classified as CWE-434 (Unrestricted Upload of File with Dangerous Type), a file upload vulnerability that enables authenticated Remote Code Execution. The core issue lies in the plugin upload mechanism's failure to properly validate the contents of uploaded ZIP archives before extracting them to a web-accessible directory.

When an administrator uploads a plugin through the AVideo interface, the application accepts ZIP archives and extracts their contents without adequately checking for potentially dangerous file types such as PHP scripts. Since the extraction destination is within the web root, any malicious PHP files included in the archive become immediately accessible and executable via direct HTTP requests.

The attack requires authentication with administrative privileges, meaning an attacker must first compromise or obtain valid administrator credentials. However, once this prerequisite is met, the path to full server compromise is straightforward and reliable.

Root Cause

The root cause of this vulnerability is insufficient validation of file types during the plugin import process. The application fails to implement proper server-side file type restrictions that would prevent executable scripts from being included in uploaded plugin packages. Specifically, the extraction routine does not filter or sanitize the contents of the ZIP archive, allowing arbitrary file types—including PHP scripts—to be placed in web-accessible directories where they can be executed by the web server.

Attack Vector

The attack is network-based and requires authenticated access with administrative privileges. An attacker with valid administrator credentials can exploit this vulnerability through the following attack flow:

1. Authenticate to the AVideo administrative interface
2. Navigate to the plugin upload/import functionality
3. Create a malicious ZIP archive containing a PHP web shell or other executable payload
4. Upload the crafted archive through the plugin interface
5. Access the extracted malicious PHP file directly via its web-accessible URL
6. Execute arbitrary commands on the server with the privileges of the web server process

The vulnerability exploitation is straightforward once administrative access is obtained. The attacker crafts a ZIP file containing malicious PHP code, uploads it through the legitimate plugin mechanism, and then accesses the uploaded file to trigger execution. This can result in complete server takeover, allowing data exfiltration, malware deployment, or use of the compromised server for further attacks.

Detection Methods for CVE-2026-28502

Indicators of Compromise

• Unexpected PHP files appearing in plugin directories, particularly those with obfuscated code or web shell characteristics
• Unusual administrative login patterns or access from unfamiliar IP addresses
• Suspicious plugin upload activities, especially ZIP files containing PHP scripts
• Outbound network connections from the web server to unknown destinations
• Web server process spawning unexpected child processes or executing system commands

Detection Strategies

• Monitor file system changes in the AVideo plugin directories for newly created or modified PHP files
• Implement web application firewall (WAF) rules to detect and block attempts to upload ZIP files containing PHP content
• Review web server access logs for requests to unusual PHP files within plugin directories
• Deploy endpoint detection to identify web shells or backdoors in the web root
• Analyze authentication logs for unusual administrative login attempts

Monitoring Recommendations

• Enable detailed logging for the plugin upload functionality and administrative actions
• Configure file integrity monitoring for all web-accessible directories
• Set up alerts for administrative authentication from new or unusual source IPs
• Monitor for suspicious POST requests to plugin upload endpoints
• Track outbound connections from the web server for potential command and control activity

How to Mitigate CVE-2026-28502

Immediate Actions Required

• Upgrade WWBN AVideo to version 24.0 or later immediately
• Audit existing plugin directories for any suspicious or unexpected PHP files
• Review administrative access logs for any indication of exploitation
• Restrict administrative access to trusted IP addresses where possible
• Implement strong multi-factor authentication for all administrator accounts

Patch Information

WWBN has released version 24.0 of AVideo which addresses this vulnerability. The fix is available through the GitHub AVideo Release 24.0. For technical details about the specific code changes, refer to the GitHub Commit Details. Additional security information can be found in the GitHub Security Advisory GHSA-v8jw-8w5p-23g3.

Workarounds

• If immediate patching is not possible, temporarily disable the plugin upload functionality
• Implement strict firewall rules limiting administrative interface access to trusted networks only
• Deploy a web application firewall with rules to inspect and block malicious file uploads
• Configure the web server to prevent PHP execution in plugin upload directories as a defense-in-depth measure
• Regularly scan plugin directories for unexpected or suspicious PHP files

# Example: Restrict PHP execution in plugin directories (Apache)
# Add to .htaccess in the plugin upload directory
# php_flag engine off
# Or for nginx, configure location block:
# location ~* /plugins/.*\.php$ {
#     deny all;
# }