CVE-2025-6019 is a Local Privilege Escalation (LPE) vulnerability affecting libblockdev, a library used for managing block devices on Linux systems. The vulnerability arises from the interaction between libblockdev and the udisks daemon, which is responsible for managing storage devices and filesystems. Typically, Polkit's "allow_active" setting permits users physically present at the machine to perform certain privileged actions based on session type. However, in this case, an "allow_active" user can exploit the way libblockdev handles filesystem images to escalate privileges to root. Specifically, udisks normally mounts user-provided filesystem images with security flags such as nosuid and nodev to prevent privilege escalation via SUID binaries or device files. The flaw allows a local attacker to craft a malicious XFS filesystem image containing a SUID-root shell and then trick udisks into resizing this image. This operation causes the malicious filesystem to be mounted with root privileges without the usual security flags, enabling execution of the SUID-root shell and granting full root control over the system. The vulnerability requires local access and a user with "allow_active" Polkit permissions, which typically means a physically present user session. The CVSS v3.1 base score is 7.0 (high), reflecting the high impact on confidentiality, integrity, and availability, but with a higher attack complexity and requiring local privileges. No known exploits in the wild have been reported as of publication. The affected product is Red Hat Enterprise Linux 10, indicating this vulnerability impacts enterprise Linux environments relying on libblockdev and udisks for device management.

For European organizations, especially those using Red Hat Enterprise Linux 10 in critical infrastructure, enterprise servers, or workstations, this vulnerability poses a significant risk. An attacker with local access—such as an insider threat, a compromised user account, or someone with physical access—could escalate their privileges to root, leading to full system compromise. This could result in unauthorized data access, disruption of services, installation of persistent malware, or lateral movement within the network. The ability to bypass standard security mount flags (nosuid, nodev) increases the risk of stealthy privilege escalation. Organizations in sectors with strict regulatory requirements around data protection and system integrity (e.g., finance, healthcare, government) could face compliance violations and reputational damage if exploited. The lack of known exploits in the wild suggests this is a newly disclosed vulnerability, but the technical feasibility means attackers may develop exploits rapidly, especially in environments where local access is possible.

1. Immediate patching: Apply any available patches or updates from Red Hat addressing CVE-2025-6019 as soon as they are released. Monitor Red Hat advisories closely. 2. Restrict Polkit "allow_active" permissions: Review and tighten Polkit policies to limit which users can perform privileged actions, especially on systems exposed to multiple users or in shared environments. 3. Limit local access: Enforce strict physical and logical access controls to prevent unauthorized local logins. Use strong authentication and session locking policies. 4. Monitor udisks and libblockdev usage: Implement monitoring and alerting for unusual filesystem image operations, particularly resize requests or mounts of user-provided images. 5. Use filesystem integrity tools: Employ tools that can detect unauthorized SUID binaries or suspicious mounts. 6. Harden system configurations: Where possible, configure udisks and libblockdev to enforce security mount flags consistently, or disable automatic resizing of user-provided images if not needed. 7. Incident response readiness: Prepare to detect and respond to local privilege escalation attempts by auditing logs and employing endpoint detection and response (EDR) solutions.