CVE-2025-50286: Getgrav Grav CMS RCE Vulnerability

CVE-2025-50286 Overview

A Remote Code Execution (RCE) vulnerability has been identified in Grav CMS version 1.7.48 that allows an authenticated administrator to upload a malicious plugin via the /admin/tools/direct-install interface. Once uploaded, the plugin is automatically extracted and loaded by the CMS, enabling arbitrary PHP code execution and potentially granting attackers reverse shell access to the underlying server.

This vulnerability is classified as CWE-434 (Unrestricted Upload of File with Dangerous Type), highlighting the critical nature of improper file upload validation in content management systems. The attack leverages legitimate administrative functionality to introduce malicious code into the application environment.

Critical Impact

Authenticated administrators can achieve full remote code execution on the server hosting Grav CMS, potentially leading to complete system compromise, data exfiltration, and lateral movement within the network.

Affected Products

• Grav CMS v1.7.48
• getgrav grav (cpe:2.3:a:getgrav:grav:1.7.48:*:*:*:*:*:*:*)

Discovery Timeline

• 2025-08-06 - CVE-2025-50286 published to NVD
• 2025-11-07 - Last updated in NVD database

Technical Details for CVE-2025-50286

Vulnerability Analysis

This vulnerability resides in the direct-install functionality of Grav CMS's administrative interface. The /admin/tools/direct-install endpoint is designed to allow administrators to install plugins by uploading ZIP archives. However, the implementation fails to adequately validate the contents of uploaded plugin packages before extraction and execution.

When a malicious plugin archive is uploaded through this interface, the CMS automatically extracts the contents and loads the plugin code without sufficient security checks. This allows an attacker with administrative credentials to introduce arbitrary PHP code into the application's execution context. The uploaded code runs with the same privileges as the web server process, potentially enabling full server compromise.

The vulnerability has an EPSS score of 63.051% (98.4th percentile), indicating a high probability of exploitation in the wild. An ExploitDB entry is available for this vulnerability, demonstrating active interest from the security research community.

Root Cause

The root cause is insufficient validation of uploaded plugin packages in the direct-install functionality. The application fails to properly sanitize and verify the contents of uploaded ZIP archives before extracting and executing the contained PHP files. This represents a classic unrestricted file upload vulnerability (CWE-434) where dangerous file types can be uploaded and subsequently executed by the application.

Attack Vector

The attack requires network access to the Grav CMS administrative interface and valid administrator credentials. An attacker would craft a malicious plugin package containing PHP code designed to execute arbitrary commands on the server. The attack flow involves:

1. Authenticating to the Grav CMS admin panel with valid credentials
2. Navigating to the direct-install interface at /admin/tools/direct-install
3. Uploading a crafted ZIP archive containing malicious PHP code disguised as a legitimate plugin
4. The CMS automatically extracts and loads the plugin, executing the malicious PHP code
5. The attacker gains code execution, potentially establishing a reverse shell for persistent access

The vulnerability is accessible over the network and can result in complete compromise of confidentiality, integrity, and availability of the affected system. For technical details and proof-of-concept information, refer to the GitHub PoC Repository.

Detection Methods for CVE-2025-50286

Indicators of Compromise

• Unexpected or unrecognized plugins appearing in the Grav CMS plugins directory
• Suspicious HTTP POST requests to /admin/tools/direct-install endpoint
• New PHP files created in plugin directories with unusual names or obfuscated content
• Outbound network connections from the web server to unknown IP addresses (potential reverse shell activity)
• Web server process spawning unexpected child processes or shell instances

Detection Strategies

• Monitor web server access logs for POST requests to /admin/tools/direct-install and correlate with plugin installation activity
• Implement file integrity monitoring on the Grav CMS installation directory, particularly the user/plugins/ directory
• Deploy web application firewall (WAF) rules to inspect uploaded ZIP files for PHP content and suspicious patterns
• Configure network monitoring to detect outbound connections from the web server to non-standard ports

Monitoring Recommendations

• Enable detailed logging for all administrative actions within Grav CMS
• Set up alerts for new plugin installations or modifications to existing plugins
• Monitor for PHP execution patterns indicative of web shells, such as calls to system(), exec(), shell_exec(), or passthru()
• Review administrative user accounts regularly and audit access logs for unauthorized login attempts

How to Mitigate CVE-2025-50286

Immediate Actions Required

• Restrict access to the Grav CMS administrative interface to trusted IP addresses only
• Review all installed plugins and remove any unrecognized or suspicious entries
• Audit administrator accounts and revoke access for any unnecessary or compromised accounts
• Implement strong authentication mechanisms such as multi-factor authentication for admin access
• Consider temporarily disabling the direct-install functionality until a patch is available

Patch Information

No vendor advisory or official patch information is currently available from getgrav. Organizations should monitor the official Grav CMS security channels and GitHub repository for security updates. Until an official patch is released, implementing the workarounds below is strongly recommended.

For the latest information on this vulnerability, refer to the GitHub PoC Repository and monitor official Grav CMS communications.

Workarounds

• Disable the direct-install feature by modifying server configuration to block access to /admin/tools/direct-install
• Implement IP-based access controls to limit administrative interface access to trusted networks only
• Deploy a reverse proxy with request filtering to block potentially malicious file uploads
• Use file system permissions to make the plugins directory read-only, preventing new plugin installations

# Block access to direct-install in Apache (.htaccess)
<LocationMatch "/admin/tools/direct-install">
    Require ip 192.168.1.0/24
    # Or deny all: Require all denied
</LocationMatch>

# For Nginx, add to server block:
# location /admin/tools/direct-install {
#     allow 192.168.1.0/24;
#     deny all;
# }