CVE-2026-30512 in entervo HMI
Summary
by MITRE • 08/24/2026
A local privilege escalation vulnerability exists in the Restricted Access (Kiosk) Mode implementation of Scheidt & Bachmann entervo HMI prior to V2 R5 P0 M5. The vulnerability affects the external PDF viewer functionality used to display the application manual and its interaction with the underlying Windows operating system. An authenticated low-privileged user can escape the kiosk environment by opening the application manual in the external PDF viewer and abusing the print functionality. Successful exploitation allows execution of arbitrary commands outside the kiosk environment with local administrator privileges.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 08/24/2026
The vulnerability identified in Scheidt & Bachmann entervo HMI software prior to version V2 R5 P0 M5 represents a critical failure in the isolation mechanisms designed for Restricted Access, commonly referred to as Kiosk Mode. This mode is intended to restrict user interaction to specific applications and prevent access to underlying operating system functions, thereby securing industrial control systems against unauthorized modifications or disruptions. The core of this security flaw lies within the external PDF viewer component utilized by the HMI application to display technical documentation such as the application manual. While the interface itself may be confined within a sandboxed environment, the interaction with the host Windows operating system through standard printing subsystems introduces an unintended escape vector that undermines the integrity of the kiosk restrictions.
From a technical perspective, the flaw stems from how the external PDF viewer handles print requests when invoked by an authenticated user with low privileges. When a user initiates the print function for the application manual, the software interacts with Windows printer drivers and spooler services without adequately validating or restricting the context of these operations. This lack of strict input validation and privilege separation allows the printing process to execute commands outside the restricted kiosk environment. By exploiting this behavior, an attacker can leverage the elevated permissions associated with the print subsystem to achieve arbitrary code execution. The vulnerability effectively bypasses the intended security boundaries because the PDF viewer does not sufficiently sandbox its interaction with system-level resources during document processing and output generation tasks.
The operational impact of this local privilege escalation is severe for industrial environments relying on entervo HMI systems. An authenticated low-privileged user, who might be an operator or maintenance technician with limited access rights, can escalate their privileges to that of a local administrator. This level of access grants the attacker full control over the underlying Windows operating system running the HMI software. Consequences include the ability to install malicious software, modify critical configuration files, exfiltrate sensitive operational data, and potentially disrupt industrial processes by altering PLC logic or stopping production lines. In an OT environment where availability and integrity are paramount, such a breach can lead to significant financial losses, safety hazards, and prolonged downtime while remediation efforts are undertaken.
This vulnerability aligns with CWE-269, which describes Improper Privilege Management, specifically the failure to enforce least privilege principles during system interactions. Furthermore, it maps to MITRE ATT&CK technique T1055, Process Injection or T1034, Internal Spearphishing if used in conjunction with other vectors, but more accurately reflects T1068 Exploitation for Privilege Escalation via local exploits that abuse trusted system processes. The specific mechanism of abusing the print functionality to escape a sandboxed environment is reminiscent of historical browser and application vulnerabilities where native OS features were leveraged to break out of restricted contexts.
To mitigate this risk, immediate action should be taken by upgrading the entervo HMI software to version V2 R5 P0 M5 or later, which addresses these isolation flaws in the PDF viewer implementation. Until an upgrade is feasible, administrators should restrict physical and logical access to the HMI terminals to only those personnel who absolutely require administrative privileges. Additionally, implementing strict application whitelisting policies can prevent unauthorized execution of processes spawned by the print subsystem outside the kiosk environment. Network segmentation strategies should also be reviewed to ensure that any compromised HMI node cannot easily pivot to other critical industrial assets. Regular security audits and penetration testing focused on privilege escalation vectors within OT environments are recommended to identify similar weaknesses in other components of the control system architecture.