CVE-2025-6794

Executive Summary

CVE-2025-6794 is a critical, unauthenticated remote code execution vulnerability in Marvell QConvergeConsole, specifically within the saveAsText method. The flaw is a directory traversal (CWE-22) that allows an attacker to write arbitrary files to the filesystem, leading to code execution in the context of SYSTEM. With a CVSS score of 9.8, this vulnerability poses an extreme risk to any organization using Marvell QConvergeConsole. No patch is currently available, and no public proof-of-concept (PoC) or exploit code has been released. Immediate mitigation measures are required.

CVSS Breakdown & Threat Level

• CVSS Score: 9.8 (Critical)
• 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: High (I:H)
• Availability Impact: High (A:H)

The threat level is Critical. The vulnerability can be exploited remotely without authentication, and successful exploitation grants SYSTEM-level code execution, allowing full compromise of the affected system.

Deep Dive & Mechanics

The vulnerability resides in the saveAsText method of Marvell QConvergeConsole. This method is designed to save text data to a file, but it fails to properly validate user-supplied paths. An attacker can supply a path containing directory traversal sequences (e.g., ../) to write files outside the intended directory.

By crafting a malicious request, an attacker can write arbitrary files to the filesystem, such as a malicious DLL or executable, which can then be executed to achieve remote code execution. Since the service runs with SYSTEM privileges, the attacker gains full control over the host.

The lack of authentication requirement makes this vulnerability particularly dangerous, as any network-accessible instance of QConvergeConsole is at risk.

Vulnerable vs. Patched Code

Since no patch is available, a direct code comparison cannot be provided. However, the vulnerable code likely resembles:

def saveAsText(data, filename):
    # Vulnerable: no path validation
    with open(filename, 'w') as f:
        f.write(data)

A patched version would validate the path to ensure it stays within an allowed directory:

import os

ALLOWED_DIR = "/var/qconvergeconsole/data/"

def saveAsText(data, filename):
    # Patched: validate path
    full_path = os.path.normpath(os.path.join(ALLOWED_DIR, filename))
    if not full_path.startswith(ALLOWED_DIR):
        raise ValueError("Invalid path")
    with open(full_path, 'w') as f:
        f.write(data)

Exploitation & Lab Setup

Red Team

Lab Setup:

1. Deploy a vulnerable instance of Marvell QConvergeConsole (version unknown) in an isolated environment.
2. Ensure the service is accessible over the network.

Exploitation Steps:

1. Identify the endpoint that handles the saveAsText method (e.g., /api/saveAsText).
2. Craft a POST request with a path traversal payload:

   POST /api/saveAsText HTTP/1.1
   Host: target:port
   Content-Type: application/json
   
   {
     "data": "malicious content",
     "filename": "../../Windows/System32/malicious.dll"
   }
   

3. The file is written to the target location.
4. Trigger execution of the written file (e.g., via a scheduled task or service restart).

Note: No public exploit code is available. The above is a conceptual example.

Blue Team

Detection:

• Monitor for unusual file write operations to system directories (e.g., C:\Windows\System32\).
• Look for HTTP requests containing path traversal sequences (../, ..\\) in the filename parameter.
• Alert on any process creation from files written by the QConvergeConsole service.

Hunting:

• Search for files created by the QConvergeConsole process outside its expected data directory.
• Review web server logs for requests to the saveAsText endpoint with suspicious filenames.

Indicators of Compromise (IOCs)

• Network:
  • HTTP POST requests to /api/saveAsText with filename containing ../ or ..\\.
  • Outbound connections from the QConvergeConsole host to unknown IPs (post-exploitation C2).
• File System:
  • Unexpected files in C:\Windows\System32\, C:\Windows\Temp\, or other system directories.
  • Files with suspicious extensions (.dll, .exe, .ps1) written by the QConvergeConsole process.
• Process:
  • Child processes spawned by the QConvergeConsole service (e.g., cmd.exe, powershell.exe).

Detection Engineering

YARA Rule

rule CVE_2025_6794_Marvell_QConvergeConsole {
    meta:
        description = "Detects path traversal attempts in Marvell QConvergeConsole saveAsText method"
        author = "Valters IT"
        date = "2025-01-01"
        reference = "CVE-2025-6794"
    strings:
        $path_traversal = /\.\.(\/|\\)/
        $method = "saveAsText"
    condition:
        $method and $path_traversal
}

Sigma Rule

title: CVE-2025-6794 - Marvell QConvergeConsole Directory Traversal
id: 12345678-1234-1234-1234-123456789abc
status: experimental
description: Detects path traversal attempts in Marvell QConvergeConsole saveAsText method
author: Valters IT
date: 2025-01-01
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2025-6794
logsource:
    category: webserver
    product: apache
    service: http
detection:
    selection:
        cs-method: 'POST'
        cs-uri-stem: '/api/saveAsText'
        cs-uri-query|contains: '..'
    condition: selection
falsepositives:
    - Legitimate use of path traversal in non-exploit scenarios (rare)
level: critical

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-6794 - Marvell QConvergeConsole Directory Traversal"; flow:to_server,established; content:"POST"; http_method; content:"/api/saveAsText"; http_uri; content:".."; http_client_body; classtype:attempted-admin; sid:1000001; rev:1;)

Remediation & Mitigation

• Immediate: If possible, disable the saveAsText functionality or restrict access to the QConvergeConsole interface to trusted IPs only.
• Network: Place QConvergeConsole behind a firewall or WAF with rules to block path traversal patterns.
• Monitoring: Implement the detection rules above to identify exploitation attempts.
• Patch: Monitor Marvell's advisory channels for a patch. Apply as soon as available.
• Workaround: If the service is not critical, consider decommissioning it until a patch is released.

Valters IT
Senior DevSecOps & Cyber Threat Intelligence Expert