CVE-2025-57848 in OpenShift Virtualization
Summary
by MITRE • 10/23/2025
A container privilege escalation flaw was found in certain Container-native Virtualization images. This issue stems from the /etc/passwd file being created with group-writable permissions during build time. In certain conditions, an attacker who can execute commands within an affected container, even as a non-root user, can leverage their membership in the root group to modify the /etc/passwd file. This could allow the attacker to add a new user with any arbitrary UID, including UID 0, leading to full root privileges within the container.
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Analysis
by VulDB Data Team • 03/07/2026
This vulnerability represents a critical privilege escalation flaw in container-native virtualization environments that directly undermines container security boundaries. The issue manifests when container images are built with improper file permissions, specifically the /etc/passwd file being created with group-writable permissions. This configuration violates fundamental security principles of least privilege and proper access control enforcement. According to CWE-732, this vulnerability falls under inadequate permissions for critical resources, where the system fails to properly restrict access to essential system files that control user authentication and authorization. The flaw enables attackers to exploit the container's trust model by leveraging group membership rather than direct privilege escalation techniques, making it particularly dangerous in multi-tenant or shared infrastructure environments.
The technical execution of this vulnerability relies on the attacker's ability to gain command execution within the container environment, which can occur through various attack vectors such as application vulnerabilities, misconfigured container settings, or social engineering tactics. Once inside the container, the attacker can leverage their membership in the root group to modify the /etc/passwd file, effectively bypassing normal user authentication mechanisms. This exploitation technique aligns with ATT&CK technique T1068, which describes privilege escalation through local exploitation, and specifically targets the container's user management system. The ability to add arbitrary users with UID 0 allows the attacker to achieve full root privileges within the container, effectively breaking out of the container's isolation boundaries. This represents a complete compromise of the container's security model, where the container's isolation properties are rendered ineffective due to improper file permissions during the build process.
The operational impact of this vulnerability extends beyond immediate privilege escalation, creating persistent security risks that can affect entire containerized environments. Container-native virtualization systems that rely on this flawed configuration become vulnerable to attackers who can execute commands within any affected container, regardless of their initial user privileges. This vulnerability directly impacts the security posture of organizations using container-native virtualization solutions, potentially allowing attackers to move laterally within containerized infrastructures, access sensitive data, or establish persistent backdoors. The flaw is particularly concerning because it can be exploited without requiring elevated privileges initially, making it accessible to attackers who have gained minimal access through other means. Organizations deploying container-native virtualization technologies must consider this vulnerability as a critical risk that could compromise their entire container orchestration environment, potentially affecting multiple containers and services running on the same infrastructure. The vulnerability also impacts compliance with security standards such as NIST SP 800-190 and ISO/IEC 27001, which require proper access control and privilege management in containerized environments.
Mitigation strategies should focus on immediate remediation of the build process to ensure proper file permissions are enforced during container image creation. Container images must be rebuilt with /etc/passwd files having restrictive permissions, typically owned by root with no group or world write permissions. Organizations should implement automated security scanning during the container build process to identify and prevent the creation of vulnerable images. The principle of least privilege must be enforced by ensuring that no group memberships or file permissions allow for unauthorized modification of critical system files. Additionally, organizations should consider implementing container runtime security controls such as read-only root filesystems, user namespace mapping, and proper SELinux or AppArmor policies to further limit the impact of such vulnerabilities. Regular security audits of container images and build processes should be conducted to prevent similar issues from reoccurring, and security teams should establish clear policies for container image management that include proper access control and permission enforcement.