CVE-2025-32957: Basercms Basercms RCE Vulnerability

CVE-2025-32957 Overview

CVE-2025-32957 is a critical vulnerability in baserCMS, a popular website development framework. The vulnerability exists in the application's restore function, which allows users to upload a .zip file that is then automatically extracted. A PHP file inside the archive is included using require_once without validating or restricting the filename. This flaw enables an attacker to craft a malicious PHP file within the zip archive and achieve arbitrary code execution when it is included by the application.

Critical Impact

An authenticated attacker with high privileges can achieve arbitrary code execution on the target server by uploading a malicious ZIP file containing a crafted PHP payload, potentially leading to complete system compromise.

Affected Products

• baserCMS versions prior to 5.2.3
• All baserCMS installations using the restore functionality
• Web servers running vulnerable baserCMS deployments

Discovery Timeline

• 2026-03-31 - CVE-2025-32957 published to NVD
• 2026-04-01 - Last updated in NVD database

Technical Details for CVE-2025-32957

Vulnerability Analysis

This vulnerability is classified as CWE-434 (Unrestricted Upload of File with Dangerous Type) and represents a severe arbitrary code execution risk. The flaw exists in the restore functionality where the application extracts uploaded ZIP archives and subsequently includes PHP files using require_once without proper validation.

The attack can be executed over the network and requires high privileges (administrative access) but no user interaction. Once exploited, the attacker gains the ability to execute arbitrary PHP code on the server with the same privileges as the web server process, potentially resulting in complete confidentiality, integrity, and availability compromise of the affected system.

Root Cause

The root cause of this vulnerability is the lack of proper input validation and filename restriction when processing files extracted from user-uploaded ZIP archives. The application blindly uses require_once to include PHP files from the extracted archive without verifying that the files are legitimate backup components or sanitizing the filenames. This allows an attacker to inject arbitrary PHP code that will be executed in the context of the web application.

Attack Vector

The attack vector is network-based and requires the attacker to have high-level privileges (typically administrative access) to the baserCMS application. The attacker crafts a malicious ZIP archive containing a PHP file with arbitrary code. When this archive is uploaded through the restore function, the application extracts the contents and includes the malicious PHP file using require_once, triggering code execution.

The vulnerability exploits the trust placed in uploaded archive contents. Since the restore function is designed to restore backups, it expects legitimate backup files. However, without proper validation, an attacker can abuse this functionality to inject and execute malicious code.

Detection Methods for CVE-2025-32957

Indicators of Compromise

• Suspicious .zip file uploads to the baserCMS restore endpoint
• Unusual PHP files appearing in directories accessible by the restore function
• Unexpected server process activity or outbound connections following restore operations
• Web server logs showing restore function access followed by unusual behavior

Detection Strategies

• Monitor file upload activity to the baserCMS restore functionality for unexpected patterns
• Implement file integrity monitoring on directories where ZIP archives are extracted
• Review web server access logs for suspicious restore function invocations
• Analyze PHP error logs for unexpected require_once failures or execution patterns

Monitoring Recommendations

• Enable detailed logging for all file upload and restore operations in baserCMS
• Configure web application firewall (WAF) rules to inspect uploaded ZIP file contents
• Implement real-time alerting for administrative function usage, especially the restore feature
• Deploy endpoint detection and response (EDR) solutions to detect post-exploitation activity

How to Mitigate CVE-2025-32957

Immediate Actions Required

• Upgrade baserCMS to version 5.2.3 or later immediately
• Restrict access to the restore functionality to only essential administrators
• Audit recent restore function usage and uploaded ZIP files for potential compromise
• Review server logs for any indicators of exploitation

Patch Information

The baserCMS development team has addressed this vulnerability in version 5.2.3. The patch implements proper validation and restriction of filenames when processing files extracted from uploaded ZIP archives before including them with require_once. Organizations should upgrade to this version as soon as possible.

For detailed patch information, refer to the BaserCMS Release Version 5.2.3 and the GitHub Security Advisory GHSA-hv78-cwp4-8r7r.

Workarounds

• Temporarily disable the restore functionality if patching is not immediately possible
• Implement network-level access controls to restrict access to the baserCMS admin panel
• Deploy a web application firewall (WAF) with rules to inspect and block malicious ZIP uploads
• Use file system permissions to restrict write access to directories used by the restore function

# Example: Restrict access to baserCMS admin panel via Apache configuration
<Directory "/var/www/html/basercms/admin">
    # Restrict to trusted IP addresses only
    Require ip 192.168.1.0/24
    Require ip 10.0.0.0/8
</Directory>