CVE-2025-11546 in CLUSTERPRO X
Summary
by MITRE • 11/07/2025
CLUSTERPRO X for Linux 4.0, 4.1, 4.2, 5.0, 5.1 and 5.2 and EXPRESSCLUSTER X for Linux 4.0, 4.1, 4.2, 5.0, 5.1 and 5.2, CLUSTERPRO X SingleServerSafe for Linux 4.0, 4.1, 4.2, 5.0, 5.1 and 5.2, EXPRESSCLUSTER X SingleServerSafe for Linux 4.0, 4.1, 4.2, 5.0, 5.1 and 5.2 allows an attacker sends specially crafted network packets to the product, arbitrary OS commands may be executed without authentication.
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Analysis
by VulDB Data Team • 11/08/2025
CVE-2025-11546 represents a critical remote code execution vulnerability affecting multiple versions of Fujitsu's clustering software products including CLUSTERPRO X for Linux, EXPRESSCLUSTER X for Linux, and their SingleServerSafe variants. This vulnerability stems from insufficient input validation within the network packet processing components of these clustering solutions, which operate at the system level to manage high availability and failover operations. The flaw exists in the network communication protocols used by these products to coordinate cluster nodes, specifically when processing incoming packets from network interfaces. Attackers can exploit this vulnerability by crafting malicious network packets that bypass authentication mechanisms and directly invoke operating system commands through the vulnerable software components. The vulnerability is particularly dangerous because it operates without requiring any authentication credentials, making it accessible to any network entity that can reach the affected systems. This represents a classic example of a buffer overflow or injection vulnerability where malformed input is processed without proper sanitization, allowing arbitrary code execution at the privilege level of the affected service account. The impact extends beyond simple command execution as these clustering products typically run with elevated privileges to manage system resources and cluster configurations, potentially allowing attackers to gain complete system compromise.
The technical exploitation of this vulnerability follows patterns consistent with CWE-77 and CWE-78 classification standards, where command injection occurs due to insufficient sanitization of user-supplied data. The ATT&CK framework categorizes this as a remote code execution technique under T1059, specifically targeting process injection and command execution capabilities. The vulnerability affects a wide range of product versions across multiple release lines, indicating a fundamental design flaw that spans the software architecture rather than being isolated to a single component. Network-based exploitation occurs through standard TCP/IP communication protocols used by the clustering software to maintain cluster membership and coordinate failover operations. The attack vector demonstrates a failure in the principle of least privilege and input validation, where the software assumes all incoming network traffic is legitimate without proper verification mechanisms. This vulnerability is particularly concerning in enterprise environments where clustering software often operates in critical infrastructure components such as database clusters, web application clusters, and high availability systems. The affected versions span multiple major releases, suggesting that this flaw has persisted through development cycles without adequate security review processes.
The operational impact of CVE-2025-11546 extends far beyond immediate system compromise, potentially affecting entire cluster configurations and business continuity operations. Organizations utilizing these clustering solutions face risks including unauthorized access to critical system resources, data exfiltration, and complete system takeover without any indication of compromise through traditional security monitoring. The vulnerability's authentication bypass nature means that network-based attacks can occur from external networks without requiring insider knowledge or credentials, significantly expanding the attack surface. In clustered environments, compromise of a single node can potentially lead to cascading failures across the entire cluster, affecting multiple systems simultaneously. The exploitation process typically involves crafting network packets that trigger the vulnerable code path, followed by execution of arbitrary commands with the privileges of the affected service account. This could include privilege escalation to root access, installation of backdoors, or modification of cluster configuration files that affect system availability. The vulnerability also poses risks to compliance requirements as it could enable unauthorized access to sensitive data and system configurations that are typically protected by cluster security policies.
Mitigation strategies for CVE-2025-11546 should focus on immediate network segmentation and access control measures to prevent unauthorized network access to affected systems. Organizations should implement firewall rules to restrict access to the specific ports and protocols used by the clustering software, particularly those used for cluster communication and management interfaces. The recommended approach includes disabling unnecessary network services and implementing network access control lists that only permit trusted network segments to communicate with the affected systems. Software vendors should provide immediate security patches addressing the input validation flaws in the network packet processing components. System administrators should consider implementing intrusion detection systems that monitor for suspicious network traffic patterns consistent with the exploitation of this vulnerability. Additionally, organizations should conduct comprehensive vulnerability assessments to identify all instances of the affected software across their network infrastructure and implement proper network monitoring to detect potential exploitation attempts. Regular security updates and patch management procedures should be enforced across all clustering software installations to prevent similar vulnerabilities from persisting in future releases. The remediation process should also include reviewing and updating cluster security policies to ensure that the principle of least privilege is maintained and that only authorized entities can communicate with the clustering services.