CVE-2025-53391 is a local privilege escalation vulnerability found in the Debian package zulucrypt_6.2.0-1, specifically related to the zuluPolkit/CMakeLists.txt configuration file. The vulnerability arises from insecure PolicyKit (polkit) settings, namely the allow_any, allow_inactive, and allow_active permissions, which are configured in a way that permits any local user to escalate their privileges to root. PolicyKit is a system service used to define and handle authorizations for privileged operations on Linux systems. Improper configuration of PolicyKit rules can lead to unauthorized privilege escalations. In this case, the zulucrypt package’s PolicyKit rules are overly permissive, allowing local users—without authentication or restrictions—to execute privileged actions. This vulnerability does not require remote access or network interaction; it is exploitable by any local user with access to the affected system. The lack of a CVSS score indicates that the vulnerability is newly published and has not yet been fully assessed or scored. There are no known exploits in the wild at the time of publication, and no patches or mitigation links have been provided yet. The affected versions are not explicitly specified beyond the Debian zulucrypt_6.2.0-1 package, suggesting that this vulnerability is tied to this particular release or configuration. Given that zulucrypt is a disk encryption management tool, the vulnerability could allow attackers to bypass encryption protections by gaining root privileges, potentially exposing sensitive data and system integrity.

For European organizations, this vulnerability poses a significant risk, especially for those relying on Debian-based systems with zulucrypt installed for disk encryption management. The ability for any local user to escalate privileges to root undermines the security model of these systems, potentially allowing attackers to access or modify sensitive data, install persistent malware, or disrupt system operations. Organizations in sectors with strict data protection requirements, such as finance, healthcare, and government, could face severe confidentiality breaches and compliance violations if exploited. Since the vulnerability requires local access, the threat is heightened in environments where multiple users share systems or where physical or remote local access is possible (e.g., via compromised user accounts or insider threats). The lack of known exploits in the wild currently reduces immediate risk but does not eliminate the potential for future exploitation. The impact extends beyond confidentiality to integrity and availability, as root access enables attackers to manipulate system files, logs, and services, potentially causing system outages or data loss.

Immediate mitigation should focus on restricting local user access to affected Debian systems running zulucrypt_6.2.0-1. Organizations should audit and harden PolicyKit configurations, specifically reviewing and correcting the allow_any, allow_inactive, and allow_active settings in the zuluPolkit/CMakeLists.txt or equivalent PolicyKit rules to enforce proper authentication and authorization checks. Until an official patch is released, consider disabling or uninstalling zulucrypt if it is not essential, or restricting its usage to trusted administrators only. Implement strict user account controls and monitoring to detect unauthorized privilege escalation attempts. Employ system integrity monitoring to detect changes to PolicyKit configurations or unauthorized root-level activities. Additionally, organizations should stay alert for updates from Debian or zulucrypt maintainers and apply patches promptly once available. Conduct regular security training to raise awareness about the risks of local privilege escalation and enforce least privilege principles to minimize the number of users with local system access.