CVE-2024-1116: Openbi Openbi RCE Vulnerability

CVE-2024-1116 Overview

A critical unrestricted file upload vulnerability has been identified in openBI, an open-source business intelligence platform. The vulnerability affects the index function within the file /application/plugins/controller/Upload.php. Due to improper validation of uploaded files, attackers can upload arbitrary files to the server, potentially leading to remote code execution.

Critical Impact

This unrestricted file upload vulnerability allows remote attackers to upload malicious files without authentication, potentially enabling complete system compromise through arbitrary code execution.

Affected Products

• openBI versions up to and including 1.0.8

Discovery Timeline

• January 31, 2024 - CVE-2024-1116 published to NVD
• November 21, 2024 - Last updated in NVD database

Technical Details for CVE-2024-1116

Vulnerability Analysis

This vulnerability is classified as CWE-434 (Unrestricted Upload of File with Dangerous Type). The affected component is the index function in /application/plugins/controller/Upload.php, which fails to properly validate or restrict the types of files that can be uploaded to the server.

In a typical exploitation scenario, an attacker can craft a malicious HTTP request to the vulnerable upload endpoint containing executable code (such as a PHP web shell). Since the application does not enforce restrictions on file types, extensions, or content validation, the malicious file is accepted and stored on the server. The attacker can then access the uploaded file directly, triggering execution of the malicious payload with the privileges of the web server.

The vulnerability is particularly dangerous because it can be exploited remotely without requiring any authentication or user interaction. This means any attacker with network access to the vulnerable openBI instance can potentially achieve complete system compromise.

Root Cause

The root cause of this vulnerability lies in the missing or inadequate file upload validation within the index function of the Upload controller. The application fails to implement proper security controls such as:

• File extension whitelisting/blacklisting
• MIME type validation
• File content inspection
• Upload directory restrictions preventing script execution

Without these safeguards, the upload functionality accepts any file type, including executable scripts that can be leveraged for remote code execution.

Attack Vector

The attack is network-based and can be executed remotely against any exposed openBI instance. An attacker would target the /application/plugins/controller/Upload.php endpoint with a specially crafted multipart form request containing a malicious file. The exploit has been publicly disclosed, meaning attack tools and techniques are readily available to threat actors.

The attack typically follows this sequence: the attacker identifies a vulnerable openBI installation, prepares a malicious payload (commonly a PHP web shell), uploads it through the vulnerable endpoint, and then accesses the uploaded file to execute arbitrary commands on the underlying server.

Detection Methods for CVE-2024-1116

Indicators of Compromise

• Unexpected files with executable extensions (.php, .phtml, .phar) appearing in upload directories
• Web server access logs showing POST requests to /application/plugins/controller/Upload.php followed by requests to newly created files
• Suspicious file creation timestamps in web-accessible directories that don't correlate with legitimate user activity

Detection Strategies

• Monitor web application logs for abnormal upload activity targeting the Upload.php controller
• Implement file integrity monitoring on web server directories to detect unauthorized file additions
• Deploy web application firewall (WAF) rules to inspect and block requests containing executable file uploads
• Review server access logs for sequential patterns of upload requests followed by direct file access attempts

Monitoring Recommendations

• Enable detailed logging on the web server and review logs for suspicious upload patterns
• Configure intrusion detection systems to alert on web shell signatures and common payload patterns
• Establish baseline metrics for upload activity and alert on anomalies
• Monitor outbound network connections from the web server that may indicate post-exploitation activity

How to Mitigate CVE-2024-1116

Immediate Actions Required

• Restrict network access to openBI installations to trusted networks only until patching is complete
• Implement web application firewall rules to block malicious upload attempts
• Review upload directories for any suspicious files and remove unauthorized content
• Consider temporarily disabling the upload functionality if not business-critical

Patch Information

At the time of this writing, users should consult the official openBI project for the latest security updates. The vulnerability affects versions up to 1.0.8, and users are advised to upgrade to the latest available version that addresses this issue. For additional technical details, refer to the VulDB advisory and the ZhaoJ Blog Post.

Workarounds

• Implement server-side file extension whitelisting to allow only safe file types (e.g., images, documents)
• Configure the web server to prevent script execution in upload directories using .htaccess or equivalent configuration
• Add authentication requirements to the upload endpoint to prevent anonymous exploitation
• Deploy a reverse proxy or WAF with rules to inspect and sanitize file uploads

# Example Apache configuration to prevent script execution in upload directories
# Add to .htaccess in the upload directory
<FilesMatch "\.(php|phtml|phar|php5|php7)$">
    Require all denied
</FilesMatch>