CVE-2025-58457 is a medium-severity vulnerability in Apache ZooKeeper versions from 3.9.0 up to but not including 3.9.4. The flaw arises from improper permission checks in the ZooKeeper AdminServer component, specifically allowing authorized clients with insufficient privileges to execute snapshot and restore commands. These commands are critical administrative operations that can affect the state and data integrity of the ZooKeeper ensemble. The root cause is linked to CWE-280, which involves improper handling of insufficient permissions or privileges, enabling users who should not have full administrative rights to perform sensitive operations. The vulnerability does not require user interaction and can be exploited remotely over the network (AV:N), with low attack complexity (AC:L) but requires some level of privileges (PR:L). The impact is limited to confidentiality as per the CVSS vector, with no direct impact on integrity or availability. The issue can be mitigated by upgrading to Apache ZooKeeper version 3.9.4, which includes the fix. Alternatively, administrators can disable the snapshot and restore commands via configuration flags (admin.snapshot.enabled and admin.restore.enabled), disable the entire AdminServer interface (admin.enableServer), or ensure that the root ACL is not overly permissive. It is important to note that ZooKeeper ACLs are not recursive, so permissions on child nodes are not affected by this vulnerability except for notifications from recursive watches. There are no known exploits in the wild at this time, but the vulnerability presents a risk if left unpatched in environments where ZooKeeper is used for coordination and configuration management.

For European organizations, the vulnerability poses a risk primarily to the confidentiality of ZooKeeper data and administrative operations. Since ZooKeeper is widely used in distributed systems, cloud services, and big data platforms, unauthorized execution of snapshot and restore commands could lead to exposure of sensitive configuration or state information. While the vulnerability does not directly affect data integrity or availability, unauthorized access to snapshot data could facilitate further attacks or data leakage. Organizations relying on ZooKeeper for critical infrastructure orchestration, such as financial institutions, telecommunications providers, and cloud service operators in Europe, could face operational risks if attackers leverage this flaw to gain insights into system states or configurations. The medium severity indicates that while exploitation is possible, it requires some level of privilege, limiting the attack surface to insiders or compromised accounts. Nonetheless, the potential for privilege escalation or lateral movement within networks makes timely mitigation important to maintain security posture and compliance with European data protection regulations such as GDPR.

European organizations should prioritize upgrading Apache ZooKeeper to version 3.9.4 or later to fully remediate this vulnerability. If immediate upgrade is not feasible, administrators should disable the snapshot and restore commands by setting admin.snapshot.enabled and admin.restore.enabled to false in the ZooKeeper configuration. Additionally, disabling the entire AdminServer interface via admin.enableServer can prevent exploitation but may impact administrative functionality. It is critical to audit and tighten ZooKeeper ACLs, ensuring that the root ACL does not grant open or overly permissive access, especially avoiding any wildcard or anonymous permissions. Given that ACLs are not recursive, special attention should be paid to permissions on parent nodes and the configuration of recursive watches. Regular monitoring of ZooKeeper logs for unusual administrative command executions and network access patterns can help detect attempted exploitation. Implementing network segmentation and restricting access to the AdminServer interface to trusted management networks will further reduce risk. Finally, organizations should incorporate this vulnerability into their patch management and incident response plans to ensure timely detection and remediation.