Westermo Network Technologies WeOS 5

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1. EXECUTIVE SUMMARY

• CVSS v4 8.7
• ATTENTION: Exploitable remotely
• Vendor: Westermo Network Technologies
• Equipment: WeOS 5
• Vulnerability: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

2. RISK EVALUATION

Successful exploitation of this vulnerability could allow an attacker with administrative permissions to execute commands that would typically be inaccessible. This could allow the execution of commands with privileges beyond those normally granted to the attacker.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

Westermo reports following versions of WeOS 5, an industrial network operating system, are affected:

• WeOS 5: Versions 5.24 and later

3.2 VULNERABILITY OVERVIEW

3.2.1 IMPROPER NEAUTRALIZATION OF SPECIAL ELEMENTS USED IN AN OS COMMAND ('OS COMMAND INJECTION') CWE-78

Westermo has identified a vulnerability in WeOS 5 that could potentially be used to inject OS commands due to unsafe handling of media definitions.

CVE-2025-46418 has been assigned to this vulnerability. A CVSS v3.1 base score of 7.6 has been calculated; the CVSS vector string is (CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:C/C:H/I:H/A:H).

A CVSS v4 score has also been calculated for CVE-2025-46418. A base score of 8.7 has been calculated; the CVSS vector string is (CVSS:4.0/AV:N/AC:H/AT:N/PR:H/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H).

3.3 BACKGROUND

• CRITICAL INFRASTRUCTURE SECTORS: Commercial Facilities, Critical Manufacturing, Energy, Water and Wastewater Systems
• COUNTRIES/AREAS DEPLOYED: Worldwide
• COMPANY HEADQUARTERS LOCATION: Sweden

3.4 RESEARCHER

Westermo reported this vulnerability to CISA.

4. MITIGATIONS

Westermo recommends the following mitigations which do not require a software update:

• Limit administration account access to trusted parties.
• Use best practices for passwords related to administration accounts.

For more information refer to Westermo's security advisory Westermo-25-07.

CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability, such as:

• Minimize network exposure for all control system devices and/or systems, ensuring they are not accessible from the Internet.
• Locate control system networks and remote devices behind firewalls and isolating them from business networks.
• When remote access is required, use more secure methods, such as virtual private networks (VPNs), recognizing VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize VPN is only as secure as the connected devices.

CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.

CISA also provides a section for control systems security recommended practices on the ICS webpage on cisa.gov/ics. Several CISA products detailing cyber defense best practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.

CISA encourages organizations to implement recommended cybersecurity strategies for proactive defense of ICS assets.

Additional mitigation guidance and recommended practices are publicly available on the ICS webpage at cisa.gov/ics in the technical information paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies.

Organizations observing suspected malicious activity should follow established internal procedures and report findings to CISA for tracking and correlation against other incidents.

CISA also recommends users take the following measures to protect themselves from social engineering attacks:

• Do not click web links or open attachments in unsolicited email messages.
• Refer to Recognizing and Avoiding Email Scams for more information on avoiding email scams.
• Refer to Avoiding Social Engineering and Phishing Attacks for more information on social engineering attacks.

No known public exploitation specifically targeting this vulnerability has been reported to CISA at this time. This vulnerability has a high attack complexity.

5. UPDATE HISTORY

• September 18, 2025 - Initial Republication of Westermo's security advisory Westermo-25-07

• Westermo