CVE-2025-43766: Liferay DXP RCE Vulnerability

CVE-2025-43766 Overview

CVE-2025-43766 is an unrestricted file upload vulnerability affecting Liferay Portal and Liferay Digital Experience Platform (DXP). The vulnerability exists within the style books component, which fails to properly validate uploaded files. This allows authenticated attackers with sufficient privileges to upload malicious files that are subsequently processed by the application, enabling arbitrary code execution within the affected environment.

The flaw represents a classic CWE-434 (Unrestricted Upload of File with Dangerous Type) scenario where the application does not adequately restrict the types of files that can be uploaded through the style books functionality. When exploited, attackers can leverage this weakness to execute arbitrary code on the underlying server, potentially leading to complete system compromise.

Critical Impact

Authenticated attackers can achieve arbitrary code execution on affected Liferay Portal and DXP installations by uploading malicious files through the style books component, potentially compromising the entire platform and underlying infrastructure.

Affected Products

• Liferay Portal 7.4.0 through 7.3.3.131
• Liferay DXP 2024.Q4.0, 2024.Q3.1 through 2024.Q3.13, 2024.Q2.0 through 2024.Q2.13, 2024.Q1.1 through 2024.Q1.12
• Liferay DXP 7.4 GA through update 92

Discovery Timeline

• 2025-08-23 - CVE-2025-43766 published to NVD
• 2025-12-12 - Last updated in NVD database

Technical Details for CVE-2025-43766

Vulnerability Analysis

This vulnerability stems from insufficient file type validation in the style books component of Liferay Portal and DXP. The style books feature allows administrators and privileged users to customize the visual presentation of the platform. However, the implementation fails to properly restrict which file types can be uploaded through this mechanism.

When a user uploads a file to the style books component, the application processes it within the execution environment without adequate security controls. This processing behavior creates an opportunity for attackers to upload executable content that the server will interpret and run. The attack requires network access and authenticated privileges, but once those conditions are met, successful exploitation leads to code execution with the privileges of the Liferay application server process.

The impact includes potential unauthorized access to sensitive data stored within the portal, modification of application integrity, and limited availability impact. Organizations running affected versions should prioritize remediation, as exploitation could allow attackers to establish persistent access to the compromised system.

Root Cause

The root cause is improper input validation in the style books file upload functionality. The application fails to implement a secure allowlist of permitted file types or to properly validate file contents against their declared types. This allows dangerous file types to bypass upload restrictions and be processed by the application server.

Attack Vector

The attack is conducted over the network against the Liferay web interface. An attacker must first authenticate to the system with privileges sufficient to access the style books component. The attacker then crafts a malicious file designed to execute code when processed by the application. Upon uploading this file through the style books interface, the Liferay environment processes the file content, triggering code execution.

The vulnerability does not require user interaction beyond the initial authentication, and exploitation can be performed through standard HTTP requests to the application endpoints responsible for handling style book uploads.

Detection Methods for CVE-2025-43766

Indicators of Compromise

• Unexpected file uploads to the style books storage directories containing executable content (JSP, PHP, shell scripts, or web shells)
• Unusual process spawning from the Liferay application server (Java process spawning system commands)
• Unauthorized modifications to style book configurations or assets
• Web server logs showing POST requests to style books endpoints with unusual file extensions or MIME types

Detection Strategies

• Implement file integrity monitoring on Liferay's style books storage locations to detect unauthorized file additions
• Configure web application firewall rules to inspect file upload requests for potentially malicious payloads
• Monitor application server logs for errors or exceptions related to file processing in the style books component
• Deploy endpoint detection and response (EDR) solutions to identify post-exploitation activity such as reverse shells or lateral movement

Monitoring Recommendations

• Enable verbose logging for the style books component and file upload handlers
• Set up alerts for file uploads with non-standard extensions (e.g., .jsp, .war, .sh, .php) to the style books component
• Monitor outbound network connections from the Liferay server for potential command-and-control activity
• Track privilege escalation attempts and new user account creation following suspicious file uploads

How to Mitigate CVE-2025-43766

Immediate Actions Required

• Review all files currently stored in style books directories for unauthorized or suspicious content
• Restrict access to the style books component to only trusted administrative users
• Implement network segmentation to limit lateral movement potential if the Liferay server is compromised
• Apply the principle of least privilege to Liferay service accounts and application server processes

Patch Information

Liferay has acknowledged this vulnerability and published a security advisory. Organizations should consult the Liferay Security Advisory for CVE-2025-43766 for the latest patch information and upgrade to a fixed version as soon as possible.

Affected organizations running Liferay Portal versions 7.4.0 through 7.3.3.131 or Liferay DXP versions through 2024.Q4.0 and 7.4 updates through update 92 should plan immediate remediation activities.

Workarounds

• Disable the style books feature if it is not required for business operations until a patch can be applied
• Implement strict file type validation at the web server or reverse proxy level to block potentially dangerous file uploads
• Configure the application server to prevent execution of uploaded files by restricting script handler mappings
• Deploy a web application firewall (WAF) with rules specifically designed to detect and block file upload attacks

# Example: Restrict file types at the web server level (Apache)
# Add to Liferay virtual host configuration
<Directory "/opt/liferay/osgi/stylebooks">
    # Disable script execution
    Options -ExecCGI
    RemoveHandler .jsp .jspx .php .sh
    
    # Only allow specific safe file types
    <FilesMatch "\.(css|json|png|jpg|svg)$">
        Allow from all
    </FilesMatch>
    
    <FilesMatch "\.(?!css$|json$|png$|jpg$|svg$)">
        Deny from all
    </FilesMatch>
</Directory>