CVE-2024-11311: Trcore DVC Path Traversal Vulnerability

CVE-2024-11311 Overview

CVE-2024-11311 is a critical Path Traversal vulnerability affecting TRCore DVC that combines directory traversal with unrestricted file upload capabilities. The vulnerability allows unauthenticated remote attackers to upload arbitrary files to any directory on the target system, enabling arbitrary code execution through the deployment of webshells.

Critical Impact

Unauthenticated remote attackers can achieve arbitrary code execution by uploading malicious webshells to any directory on vulnerable TRCore DVC installations, potentially leading to complete system compromise.

Affected Products

• TRCore DVC (all versions)

Discovery Timeline

• 2024-11-18 - CVE-2024-11311 published to NVD
• 2024-11-20 - Last updated in NVD database

Technical Details for CVE-2024-11311

Vulnerability Analysis

This vulnerability combines two dangerous weaknesses classified under CWE-22 (Improper Limitation of a Pathname to a Restricted Directory) and CWE-23 (Relative Path Traversal). The TRCore DVC application fails to properly validate and sanitize file paths provided during file upload operations, while simultaneously lacking restrictions on the types of files that can be uploaded.

The combination of these flaws creates a particularly dangerous attack surface. An attacker can exploit the path traversal weakness to escape the intended upload directory and write files to arbitrary locations on the filesystem. Since the application does not restrict file types, attackers can upload executable content such as webshells written in PHP, ASP, or JSP depending on the server environment.

Root Cause

The root cause stems from insufficient input validation in the file upload functionality of TRCore DVC. The application fails to:

1. Properly sanitize directory traversal sequences (such as ../) from user-supplied file paths
2. Implement allowlisting or blocklisting for permitted file types
3. Restrict uploads to a secure, non-executable directory

This design flaw allows attackers to bypass the intended upload directory constraints and place malicious files in web-accessible directories where they can be executed.

Attack Vector

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

1. Crafting a malicious HTTP request to the file upload endpoint
2. Including path traversal sequences in the filename or path parameter to navigate to a web-accessible directory
3. Uploading a webshell or other malicious executable content
4. Accessing the uploaded webshell via HTTP to execute arbitrary commands on the server

The vulnerability is particularly severe because it can be exploited by completely unauthenticated attackers, providing an initial foothold for further compromise of the target environment.

Detection Methods for CVE-2024-11311

Indicators of Compromise

• Unexpected files appearing in web-accessible directories, particularly with extensions like .php, .asp, .aspx, or .jsp
• HTTP requests containing path traversal sequences such as ../ or URL-encoded variants (%2e%2e%2f) in upload parameters
• Unusual POST requests to file upload endpoints with suspicious filenames or paths
• Web server access logs showing requests to newly created files in unexpected locations

Detection Strategies

• Monitor file upload endpoints for requests containing directory traversal patterns in filenames or path parameters
• Implement file integrity monitoring on web-accessible directories to detect unauthorized file creation
• Deploy web application firewall (WAF) rules to detect and block path traversal attempts in upload requests
• Review web server logs for anomalous file upload activity and subsequent execution requests

Monitoring Recommendations

• Enable detailed logging on TRCore DVC file upload functionality
• Configure alerts for file creation events in web root directories outside designated upload folders
• Monitor for outbound connections from the web server that may indicate webshell callback activity
• Implement regular file system audits to identify suspicious executable files in web-accessible paths

How to Mitigate CVE-2024-11311

Immediate Actions Required

• Restrict network access to TRCore DVC installations to trusted IP addresses only
• Implement web application firewall rules to block path traversal sequences in upload requests
• Audit existing web-accessible directories for unauthorized files that may indicate prior compromise
• Consider taking vulnerable systems offline until a patch is available

Patch Information

For official patch information, refer to the security advisories published by Taiwan CERT:

• Taiwan CERT Security Advisory (English)
• Taiwan CERT Security Advisory (Chinese)

Contact TRCore directly for vendor-specific patching guidance and updated software versions.

Workarounds

• Implement strict input validation on all file upload parameters, rejecting any requests containing path traversal sequences
• Configure the web server to disallow execution of uploaded files by placing the upload directory outside the web root or removing execute permissions
• Implement file type allowlisting to restrict uploads to known-safe file types only
• Deploy network segmentation to limit the impact of potential compromise

# Example: Restrict access to upload functionality via web server configuration (Apache)
<Directory "/path/to/upload/directory">
    # Disable script execution in upload directory
    Options -ExecCGI
    php_admin_flag engine off
    RemoveHandler .php .phtml .php3 .php4 .php5
    
    # Restrict access by IP (adjust as needed)
    Require ip 10.0.0.0/8
</Directory>