CVE-2025-11546 is an OS command injection vulnerability classified under CWE-78 found in NEC Corporation's CLUSTERPRO X for Linux (EXPRESSCLUSTER X for Linux) versions 4.0 through 5.2. This vulnerability arises due to improper neutralization of special elements in OS commands, allowing an attacker to inject arbitrary commands via specially crafted network packets. The vulnerability notably requires no authentication, no user interaction, and can be exploited remotely over the network, making it highly accessible to attackers. The vulnerability impacts multiple versions, indicating a long-standing issue in the product line. The CVSS 4.0 vector (AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N) reflects a network attack vector with low complexity and no privileges or user interaction required, but with high impact on confidentiality, integrity, and availability. Although no public exploits have been reported yet, the critical severity score of 9.3 underscores the potential for severe damage, including full system compromise, data theft, or disruption of clustered services. The vulnerability affects NEC’s clustering software widely used in enterprise and critical infrastructure environments to ensure high availability and fault tolerance, making it a significant risk if exploited.

For European organizations, exploitation of CVE-2025-11546 could lead to complete system compromise of critical clustering infrastructure, resulting in unauthorized access to sensitive data, disruption of high-availability services, and potential lateral movement within networks. Given the role of clustering software in maintaining uptime for critical applications, successful exploitation could cause significant operational downtime, financial losses, and reputational damage. Sectors such as telecommunications, finance, energy, and government services that rely on NEC’s clustering solutions for fault tolerance and load balancing are particularly vulnerable. The lack of authentication and user interaction requirements means attackers can remotely exploit this vulnerability without insider access, increasing the risk of widespread attacks. Additionally, the high impact on confidentiality, integrity, and availability could facilitate espionage, sabotage, or ransomware attacks targeting European enterprises and critical infrastructure.

1. Monitor NEC’s official channels for patches or updates addressing CVE-2025-11546 and apply them immediately upon release. 2. Until patches are available, implement strict network segmentation to isolate systems running CLUSTERPRO X from untrusted networks. 3. Employ ingress filtering and firewall rules to restrict access to the clustering software’s network interfaces, allowing only trusted management hosts. 4. Conduct thorough network traffic monitoring and anomaly detection to identify suspicious packets targeting the clustering software. 5. Review and harden configurations of NEC CLUSTERPRO X to minimize exposed services and disable unnecessary network-facing features. 6. Implement host-based intrusion detection systems (HIDS) to detect unusual command executions or process behaviors on affected systems. 7. Develop and test incident response plans specifically for potential exploitation scenarios involving clustering infrastructure. 8. Educate IT and security teams about the vulnerability’s characteristics to ensure rapid detection and response.