Critical Privilege Escalation Flaws in Weintek cMT X Series HMI EasyWeb Service

Critical Vulnerabilities Expose Weintek cMT X Series HMI to Privilege Escalation Attacks

The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has disclosed multiple critical vulnerabilities in Weintek cMT X Series HMI EasyWeb Service that could allow low-privileged users to escalate privileges and gain full control of affected devices. The advisory, published as ICSA-26-022-05, highlights risks to operational technology (OT) environments.

Technical Details

The vulnerabilities affect the following versions of Weintek cMT X Series HMI EasyWeb Service:

• All versions prior to v1.0.11.0 (exact affected versions not specified in the advisory)

While CISA’s advisory does not provide specific CVE IDs or detailed technical mechanisms, successful exploitation could enable attackers to:

• Escalate privileges from a low-level user account
• Gain full administrative control of the HMI device
• Execute arbitrary commands or manipulate industrial processes

The CSAF (Common Security Advisory Framework) document may contain additional technical context for security teams.

Impact Analysis

HMI (Human-Machine Interface) devices are critical components in industrial control systems (ICS), often used to monitor and control physical processes in sectors such as manufacturing, energy, and water treatment. A compromise of these devices could lead to:

• Unauthorized process manipulation (e.g., altering production parameters)
• Operational disruption (e.g., shutdowns or malfunctions)
• Lateral movement into broader OT networks
• Safety risks if exploited in safety-critical environments

The lack of authentication or authorization checks in vulnerable versions exacerbates the risk, as attackers with minimal access could exploit these flaws without requiring advanced techniques.

Recommendations

CISA urges organizations using Weintek cMT X Series HMI devices to:

1. Apply patches immediately: Upgrade to EasyWeb Service v1.0.11.0 or later to mitigate the vulnerabilities.
2. Restrict network access: Isolate HMI devices from untrusted networks, including the internet, and segment OT networks to limit lateral movement.
3. Monitor for suspicious activity: Deploy intrusion detection systems (IDS) to detect unusual privilege escalation attempts or unauthorized access.
4. Review user permissions: Audit low-privileged accounts to ensure they have only the minimum necessary access.
5. Consult the CSAF document: Security teams should review the CSAF advisory for additional technical indicators or mitigation strategies.

For further guidance, refer to CISA’s ICS Advisory (ICSA-26-022-05).