CVE-2024-2052

Executive Summary

CVE-2024-2052 is a high-severity vulnerability (CVSS 7.5) in Schneider Electric products, classified under CWE-552 (Files or Directories Accessible to External Parties). The flaw allows an unauthenticated attacker to exfiltrate files and logs by manipulating URLs to download from unintended locations. This poses a significant risk of sensitive data exposure, including configuration files, credentials, and operational logs. No public proof-of-concept (PoC) or patch details are currently available, and the EPSS score is 0.0%, indicating low exploitation activity in the wild. However, the lack of a patch and the potential for data exfiltration make this a critical concern for organizations using affected Schneider Electric systems.

CVSS Breakdown & Threat Level

• CVSS Score: 7.5 (High)
• Attack Vector: Network (AV:N)
• Attack Complexity: Low (AC:L)
• Privileges Required: None (PR:N)
• User Interaction: None (UI:N)
• Scope: Unchanged (S:U)
• Confidentiality Impact: High (C:H)
• Integrity Impact: None (I:N)
• Availability Impact: None (A:N)
• Threat Level: High – Unauthenticated remote data exfiltration with no user interaction.

Deep Dive & Mechanics

The vulnerability resides in the URL handling mechanism of Schneider Electric products. By crafting a malicious URL that points to a different directory or file path, an attacker can bypass intended access controls and download arbitrary files from the server. This is a classic path traversal or directory listing issue, but specifically tied to the download functionality. The attack does not require authentication, making it exploitable from the network perimeter.

The root cause is insufficient validation of user-supplied input in the download endpoint. The application fails to sanitize or restrict the file path, allowing an attacker to use ../ sequences or absolute paths to access files outside the intended download directory. This can lead to the exfiltration of sensitive logs, configuration files (e.g., .env, config.xml), and potentially credentials stored in plaintext.

Vulnerable vs. Patched Code

Since no patch is available, a hypothetical vulnerable code snippet and its patched version are provided for understanding.

Vulnerable Code (Python Flask example):

@app.route('/download')
def download():
    filename = request.args.get('file')
    # No validation of filename
    return send_file('/var/app/downloads/' + filename)

Patched Code:

import os
from flask import abort

@app.route('/download')
def download():
    filename = request.args.get('file')
    # Sanitize and restrict to allowed directory
    safe_path = os.path.normpath('/var/app/downloads/' + filename)
    if not safe_path.startswith('/var/app/downloads/'):
        abort(403)
    return send_file(safe_path)

Exploitation & Lab Setup

Red Team

Lab Setup:

1. Deploy a vulnerable Schneider Electric device or simulate using a web server with a download endpoint.
2. Use a tool like Burp Suite or curl to manipulate the file parameter.

Exploitation Steps:

1. Identify the download endpoint (e.g., /download?file=report.pdf).
2. Attempt path traversal: /download?file=../../../etc/passwd.
3. If successful, exfiltrate sensitive files like logs or configs.

Example curl command:

curl -v "http://target.com/download?file=../../../etc/passwd"

Blue Team

Detection:

• Monitor for unusual URL patterns containing ../ or absolute paths.
• Alert on repeated failed access attempts to restricted directories.
• Use WAF rules to block path traversal payloads.

Hunting:

• Search web server logs for requests with ../ or %2e%2e%2f patterns.
• Look for outbound data transfers from the device to unknown IPs.

Indicators of Compromise (IOCs)

• Network IOCs:
  • HTTP requests with ../ or %2e%2e%2f in the file parameter.
  • Unusual outbound connections from Schneider Electric devices to external IPs.
• File IOCs:
  • Unexpected files in download directories (e.g., /etc/passwd, config.xml).
• Log IOCs:
  • Web server logs showing 200 responses to path traversal attempts.

Detection Engineering

YARA Rule

rule CVE_2024_2052_PathTraversal {
    meta:
        description = "Detects path traversal attempts targeting CVE-2024-2052"
        author = "Valters IT"
        date = "2025-04-10"
    strings:
        $traversal1 = "../"
        $traversal2 = "..\\"
        $traversal3 = "%2e%2e%2f"
        $traversal4 = "%2e%2e\\"
    condition:
        any of them
}

Sigma Rule

title: CVE-2024-2052 Path Traversal Attempt
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects path traversal patterns in HTTP requests
author: Valters IT
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'GET'
        cs-uri-query|contains:
            - '../'
            - '..\\'
            - '%2e%2e%2f'
            - '%2e%2e\\'
    condition: selection
falsepositives:
    - Legitimate use of relative paths in some applications
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2024-2052 Path Traversal Attempt"; flow:to_server; content:"../"; http_uri; nocase; sid:1000001; rev:1;)

Remediation & Mitigation

• Immediate Actions:
  • Isolate affected Schneider Electric devices from the internet.
  • Implement strict input validation on all download endpoints.
  • Use a Web Application Firewall (WAF) to block path traversal patterns.
• Long-term Fix:
  • Apply vendor patches when available.
  • Upgrade to the latest firmware/software version.
• Compensating Controls:
  • Restrict file system permissions to limit access to sensitive files.
  • Enable logging and monitoring for anomalous file access.

Report generated by Valters IT DevSecOps & CTI Division