ABB Cylon Aspect BMS/BAS

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1. EXECUTIVE SUMMARY

• CVSS v4 9.3
• ATTENTION: Exploitable remotely/low attack complexity
• Vendor: ABB
• Equipment: ASPECT, NEXUS, MATRIX
• Vulnerabilities: Authentication Bypass Using an Alternate Path or Channel, Missing Authentication for Critical Function, Classic Buffer Overflow

2. RISK EVALUATION

Successful exploitation of these vulnerabilities could allow an attacker to assume control of the target device or perform a denial-of-service (DoS) attack.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

ABB reports that the following products are affected:

• ABB ASPECT-Enterprise ASP-ENT-x: Versions prior to 3.08.04-s01
• ABB NEXUS Series NEX-2x: Versions prior to 3.08.04-s01
• ABB NEXUS Series NEXUS-3-x: Versions prior to 3.08.04-s01
• ABB MATRIX Series MAT-x: Versions prior to 3.08.04-s01

3.2 VULNERABILITY OVERVIEW

3.2.1 AUTHENTICATION BYPASS USING AN ALTERNATE PATH OR CHANNEL CWE-288

Due to an issue in configuration, code that was intended for debugging purposes was included in the market release of the ASPECT FW allowing an attacker to bypass authentication. This vulnerability may allow an attacker to change the system time, access files, and make function calls without prior authentication. This issue affects all versions of ASPECT prior to 3.08.04-s01.

CVE-2025-53187 has been assigned to this vulnerability. A CVSS v3.1 base score of 9.8 has been calculated; the CVSS vector string is (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

A CVSS v4 score has also been calculated for CVE-2025-53187. A base score of 9.3 has been calculated; the CVSS vector string is (CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N).

3.2.2 BUFFER COPY WITHOUT CHECKING SIZE OF INPUT ('CLASSIC BUFFER OVERFLOW') CWE-120

A denial-of-service (DoS) attack is possible if access to the local network is provided to unauthorized users. This is due to a buffer copy issue that may lead to a software crash. This issue affects all versions of ASPECT.

CVE-2025-7677 has been assigned to this vulnerability. A CVSS v3.1 base score of 5.9 has been calculated; the CVSS vector string is (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H).

A CVSS v4 score has also been calculated for CVE-2025-7677. A base score of 8.2 has been calculated; the CVSS vector string is (CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N).

3.2.3 MISSING AUTHENTICATION FOR CRITICAL FUNCTION CWE-306

The ASPECT system allows users to bypass authentication. This issue affects all versions of ASPECT.

CVE-2025-7679 has been assigned to this vulnerability. A CVSS v3.1 base score of 8.1 has been calculated; the CVSS vector string is (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H).

A CVSS v4 score has also been calculated for CVE-2025-7679. A base score of 9.2 has been calculated; the CVSS vector string is (CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N).

3.3 BACKGROUND

• CRITICAL INFRASTRUCTURE SECTORS: Commercial Facilities
• COUNTRIES/AREAS DEPLOYED: Worldwide
• COMPANY HEADQUARTERS LOCATION: Switzerland

3.4 RESEARCHER

Gjoko Krstikj of Zero Science Labs reported these vulnerabilities to CISA.

4. MITIGATIONS

For more information refer to ABB's Cybersecurity Advisory 9AKK108471A4 462. The ABB advisory includes a detailed mapping of applicable mitigations for each listed vulnerability.

ABB has identified the following specific workarounds and mitigations users can apply to reduce risk:

• CVE-2025-53187: This vulnerability has been resolved in product versions 3.08.04-s01 and later.

The remaining mitigations are general security measures that apply to all vulnerabilities:

• All vulnerabilities reported in the scope of this document are exploitable only if the attackers can access the network segment where ASPECT is installed and exposed directly to the Internet. ABB therefore recommends the following guidelines to protect customer networks:
  • ASPECT devices should never be exposed directly to the Internet either via a direct ISP connection or via NAT port forwarding. If remote access to an ASPECT system is a user requirement, the system shall operate behind a firewall. Users accessing ASPECT remotely shall do this using a VPN Gateway allowing access to the network segment where ASPECT is installed and configured.
    • Note: It is crucial that the VPN Gateway and Network are set up in accordance with best industry standards and maintained in terms of security patches for all related components.
  • Authorized users shall change all default credentials during commissioning of an ASPECT system. If credentials have not been changed during commissioning state, ABB advises users to change each changeable credential at the earliest opportunity.
  • Ensure that all ASPECT products are upgraded to the latest firmware version. The latest version of ASPECT firmware can be found on the respective product homepage.

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. 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 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.

No known public exploitation specifically targeting these vulnerabilities has been reported to CISA at this time.

5. UPDATE HISTORY

• September 9, 2025: Initial Publication

• ABB