CVE-2024-11312: Trcore DVC Path Traversal Vulnerability

CVE-2024-11312 Overview

CVE-2024-11312 is a critical vulnerability affecting the DVC product from TRCore that combines a Path Traversal flaw with unrestricted file upload functionality. This dangerous combination allows unauthenticated remote attackers to upload arbitrary files to any directory on the target system, ultimately enabling arbitrary code execution through webshell deployment.

Critical Impact

Unauthenticated remote attackers can achieve complete system compromise by uploading webshells to arbitrary directories, leading to remote code execution without any prior authentication.

Affected Products

• TRCore DVC (all versions prior to patched release)

Discovery Timeline

• 2024-11-18 - CVE-2024-11312 published to NVD
• 2024-11-20 - Last updated in NVD database

Technical Details for CVE-2024-11312

Vulnerability Analysis

This vulnerability represents a severe security flaw resulting from two compounding weaknesses in the TRCore DVC application. The first weakness involves improper neutralization of special elements used in a pathname (CWE-22/CWE-23), commonly known as Path Traversal. The second weakness is the failure to restrict the types of files that can be uploaded to the server.

When exploited together, these flaws create a particularly dangerous attack surface. An attacker can craft malicious requests containing directory traversal sequences (such as ../) to escape the intended upload directory and place files anywhere on the filesystem where the web server process has write permissions. Combined with the lack of file type restrictions, this allows attackers to upload executable webshells (such as PHP, ASP, or JSP files depending on the server environment) directly into web-accessible directories.

The attack requires no authentication, making it trivially exploitable by any remote attacker who can reach the vulnerable endpoint over the network. Once a webshell is successfully uploaded, the attacker gains the ability to execute arbitrary commands on the server with the privileges of the web application process.

Root Cause

The root cause of this vulnerability stems from insufficient input validation and sanitization in the file upload functionality of TRCore DVC. Specifically, the application fails to:

1. Properly sanitize user-supplied file paths, allowing directory traversal sequences to be processed
2. Implement allowlist-based file type validation to restrict uploads to safe file extensions
3. Separate the upload directory from web-accessible paths or implement proper access controls

These fundamental security oversights in the application's file handling logic create the conditions necessary for exploitation.

Attack Vector

The attack is network-based and requires no authentication or user interaction. An attacker exploits this vulnerability by:

1. Identifying the vulnerable file upload endpoint in the TRCore DVC application
2. Crafting a malicious HTTP request containing path traversal sequences in the filename or path parameter
3. Including a webshell payload (malicious server-side script) as the file content
4. Sending the request to traverse directories and place the webshell in a web-accessible location
5. Accessing the uploaded webshell via a web browser to execute arbitrary commands

The attack can be performed with standard HTTP client tools and requires minimal technical sophistication once the vulnerable endpoint is identified. For detailed technical information, refer to the TW-CERT Security Report.

Detection Methods for CVE-2024-11312

Indicators of Compromise

• Presence of unexpected files with executable extensions (.php, .asp, .aspx, .jsp) in web-accessible directories
• Web server access logs showing requests containing path traversal sequences (../, ..%2f, %2e%2e/)
• Unusual outbound network connections from the web server process
• Modified file timestamps in critical system directories
• Evidence of command execution in web server error logs or shell history

Detection Strategies

• Deploy web application firewall (WAF) rules to detect and block path traversal patterns in HTTP requests
• Implement file integrity monitoring (FIM) on web-accessible directories to detect unauthorized file creation
• Configure intrusion detection systems (IDS) with signatures for common webshell characteristics
• Monitor for anomalous POST requests to file upload endpoints, particularly those with unusual path parameters
• Analyze web server logs for requests targeting newly created files with executable extensions

Monitoring Recommendations

• Enable detailed access logging on all web-facing TRCore DVC instances
• Set up alerts for file creation events in web root and upload directories
• Monitor process execution chains originating from web server processes
• Implement network segmentation monitoring to detect lateral movement attempts following potential compromise
• Review authentication logs for evidence of credential harvesting following webshell deployment

How to Mitigate CVE-2024-11312

Immediate Actions Required

• Restrict network access to TRCore DVC instances to trusted IP ranges only until a patch is applied
• Implement a web application firewall with rules blocking path traversal sequences
• Disable or restrict access to file upload functionality if not business-critical
• Conduct a thorough filesystem review to identify any potentially malicious files already uploaded
• Increase monitoring and logging on affected systems

Patch Information

Organizations should consult the TW-CERT Security Advisory for official guidance from the coordination center. Contact TRCore directly for information on available security patches and updated versions that address this vulnerability.

Workarounds

• Configure the web server to prevent execution of scripts in upload directories using server configuration directives
• Implement network-level access controls to limit exposure of the vulnerable application
• Use a reverse proxy with strict input validation to filter malicious requests before they reach the application
• Deploy application-level controls to enforce allowlist-based file type validation at the web server level
• Consider temporarily taking the affected system offline if it processes sensitive data and cannot be adequately protected

# Example Apache configuration to prevent script execution in upload directories
<Directory "/var/www/html/uploads">
    Options -ExecCGI -Indexes
    AllowOverride None
    RemoveHandler .php .phtml .php3 .php4 .php5 .phps
    <FilesMatch "\.(?:php|phtml|php3|php4|php5|phps)$">
        Require all denied
    </FilesMatch>
</Directory>