CVE-2025-27457 is a vulnerability identified in the Endress+Hauser MEAC300-FNADE4 device, specifically related to its use of VNC (Virtual Network Computing) for remote access. The core issue is that all communication between the VNC server on the device and its clients is transmitted in cleartext, without any encryption. This vulnerability corresponds to CWE-319, which concerns the cleartext transmission of sensitive information. Because the data is unencrypted, an attacker with network access can intercept the VNC traffic and extract sensitive information, such as authentication credentials or session data. The CVSS v3.1 score is 6.5 (medium severity), reflecting that the attack vector is network-based (AV:N), requires no privileges (PR:N), but does require user interaction (UI:R). The impact is primarily on confidentiality (C:H), with no direct impact on integrity or availability. The vulnerability affects all versions of the MEAC300-FNADE4 product, indicating a systemic design flaw in the VNC implementation. No patches or mitigations have been published yet, and there are no known exploits in the wild. The vulnerability was reserved in February 2025 and published in July 2025. Given the nature of the device—Endress+Hauser MEAC300-FNADE4 is an industrial automation or process control device—the exposure of sensitive data could lead to further targeted attacks or unauthorized access to industrial control systems if exploited.

For European organizations, especially those in industrial sectors such as manufacturing, utilities, chemical processing, and critical infrastructure, this vulnerability poses a significant risk. The MEAC300-FNADE4 is likely deployed in operational technology (OT) environments where confidentiality of control commands and credentials is critical. Interception of VNC traffic could allow attackers to harvest credentials or session data, potentially enabling unauthorized remote control or reconnaissance of industrial systems. This could lead to operational disruptions, safety hazards, or intellectual property theft. Since the vulnerability does not directly affect integrity or availability, immediate operational disruption is less likely solely from this vulnerability, but it can serve as an entry point for more severe attacks. The requirement for user interaction (UI:R) implies that exploitation may involve tricking an operator or engineer into initiating a VNC session, which is plausible in operational environments. The lack of encryption also violates many European cybersecurity regulations and standards for critical infrastructure, such as NIS Directive requirements, potentially leading to compliance issues and reputational damage.

Given the absence of official patches, European organizations should implement compensating controls immediately. First, restrict network access to the MEAC300-FNADE4 devices by segmenting OT networks and enforcing strict firewall rules to limit VNC traffic only to trusted management stations. Use VPNs or secure tunnels (e.g., IPsec or TLS-based VPNs) to encapsulate VNC sessions, ensuring encryption at the network layer. Where possible, disable VNC access if not strictly necessary or replace it with more secure remote access solutions that support encryption and strong authentication. Implement strict user training and awareness programs to reduce the risk of social engineering that could lead to user interaction exploitation. Monitor network traffic for unencrypted VNC sessions and anomalous access patterns. Finally, engage with Endress+Hauser for updates or firmware releases addressing this vulnerability and plan for timely patching once available.