CVE-2026-30804: Pandora FMS RCE Vulnerability

CVE-2026-30804 Overview

CVE-2026-30804 is an Unrestricted Upload of File with Dangerous Type vulnerability (CWE-434) affecting Pandora FMS, a popular network monitoring and IT operations management platform. This vulnerability allows authenticated attackers to upload malicious files through the file upload functionality, ultimately leading to Remote Code Execution (RCE) on the target system.

The vulnerability exists in Pandora FMS versions 777 through 800, where insufficient validation of uploaded file types enables attackers to bypass intended security restrictions and execute arbitrary code on the server.

Critical Impact

Authenticated attackers can achieve Remote Code Execution by uploading malicious files, potentially compromising the entire monitoring infrastructure and any systems connected to it.

Affected Products

• Pandora FMS versions 777 through 800

Discovery Timeline

• 2026-04-13 - CVE-2026-30804 published to NVD
• 2026-04-13 - Last updated in NVD database

Technical Details for CVE-2026-30804

Vulnerability Analysis

This vulnerability stems from inadequate file type validation in Pandora FMS's file upload functionality. The application fails to properly restrict which file types can be uploaded by authenticated users with high-privilege accounts. This oversight allows attackers to upload web shells, executable scripts, or other dangerous file types that can be subsequently executed by the web server.

Pandora FMS, as a network monitoring solution, typically has extensive access to network infrastructure and credentials for monitored systems. Compromising the Pandora FMS server through this vulnerability could provide attackers with a pivotal position to pivot throughout the network and access sensitive monitoring data.

The vulnerability requires authenticated access with high privileges, which somewhat limits the attack surface. However, in environments where multiple users have administrative access to Pandora FMS, or where credentials may have been compromised through other means, this vulnerability presents a serious risk.

Root Cause

The root cause of CVE-2026-30804 is the absence of proper file type validation and content inspection in the file upload handling mechanism. The application likely relies on client-side validation or easily spoofed file extension checks rather than implementing robust server-side validation that inspects file contents and MIME types.

Common implementation failures in file upload security include:

• Accepting user-provided file extensions without verification
• Not checking file contents against declared MIME types
• Failing to sanitize uploaded filenames
• Storing uploaded files in web-accessible directories without proper access controls

Attack Vector

The attack vector for CVE-2026-30804 is network-based, requiring no user interaction beyond the attacker's own authenticated session. An attacker with high-privileged access to the Pandora FMS web interface can exploit this vulnerability by:

1. Authenticating to the Pandora FMS web console with a high-privilege account
2. Navigating to a file upload functionality within the application
3. Uploading a malicious file (such as a PHP web shell) disguised or bypassing file type restrictions
4. Accessing the uploaded file through the web server to trigger code execution
5. Executing arbitrary commands on the underlying server with the privileges of the web server process

The exploitation does not require complex conditions and can be executed in a straightforward manner once authenticated access is obtained.

Detection Methods for CVE-2026-30804

Indicators of Compromise

• Unusual file uploads to Pandora FMS upload directories, particularly files with executable extensions (.php, .phtml, .php5, .phar)
• Web server access logs showing requests to newly created files in upload directories
• Unexpected process spawning from the web server process (e.g., www-data, apache, nginx)
• Outbound network connections initiated from the Pandora FMS server to unknown destinations

Detection Strategies

• Monitor file system changes in Pandora FMS upload and temporary directories for suspicious file creations
• Implement web application firewall (WAF) rules to detect malicious file upload attempts
• Configure SIEM alerts for unusual authentication patterns followed by file upload activity
• Analyze web server logs for POST requests to upload endpoints followed by GET requests to unusual file paths

Monitoring Recommendations

• Enable comprehensive logging for the Pandora FMS application and underlying web server
• Implement file integrity monitoring on the Pandora FMS installation directory
• Monitor for privilege escalation attempts on the Pandora FMS server
• Review authentication logs for suspicious login activity, particularly from unexpected IP addresses

How to Mitigate CVE-2026-30804

Immediate Actions Required

• Upgrade Pandora FMS to a patched version beyond version 800 that addresses this vulnerability
• Review user accounts with high privileges and remove unnecessary access
• Audit recent file uploads in the Pandora FMS application for suspicious files
• Implement network segmentation to limit the impact of potential compromise

Patch Information

Pandora FMS has published information about this vulnerability on their security advisory page. Organizations running affected versions (777 through 800) should consult this resource for specific patch details and upgrade guidance.

It is recommended to upgrade to the latest stable version of Pandora FMS that contains the security fix for this file upload vulnerability.

Workarounds

• Restrict access to Pandora FMS administrative functions to only essential personnel
• Implement additional authentication layers (MFA) for Pandora FMS administrative access
• Configure web server rules to prevent execution of uploaded files in upload directories
• Place Pandora FMS behind a reverse proxy with strict file upload filtering

# Example Apache configuration to prevent script execution in upload directories
<Directory "/var/www/pandora/upload">
    # Disable script execution
    Options -ExecCGI
    RemoveHandler .php .phtml .php5 .phar
    php_flag engine off
    
    # Deny direct access to uploaded files
    <FilesMatch "\.(php|phtml|php5|phar|cgi|pl|py)$">
        Require all denied
    </FilesMatch>
</Directory>