CVE-2019-19348 in apb-base
Summary
by MITRE
An insecure modification vulnerability in the /etc/passwd file was found in the container openshift/apb-base, affecting versions before the following 4.3.5, 4.2.21, 4.1.37, and 3.11.188-4. An attacker with access to the container could use this flaw to modify /etc/passwd and escalate their privileges.
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Analysis
by VulDB Data Team • 05/13/2024
The vulnerability identified as CVE-2019-19348 represents a critical privilege escalation flaw within the openshift/apb-base container image ecosystem. This issue stems from insecure file modification practices that allow unauthorized users to manipulate the system's user authentication database through the /etc/passwd file. The affected container image serves as a foundational component for OpenShift Application Platform builds, making this vulnerability particularly dangerous as it could be exploited across numerous containerized applications and deployment scenarios. The vulnerability exists in multiple versions including 4.3.5, 4.2.21, 4.1.37, and 3.11.188-4, indicating a widespread impact across the OpenShift platform's version spectrum.
The technical flaw manifests through improper file permissions and access controls that permit modification of the /etc/passwd file, which contains critical user account information including usernames, user identifiers, and password hashes. When an attacker gains access to a container running the vulnerable openshift/apb-base image, they can directly manipulate this file to create new user accounts with elevated privileges or modify existing accounts to gain root-level access. This vulnerability directly maps to CWE-276, which describes inadequate file permissions, and CWE-732, which covers incorrect permissions for critical resources. The flaw essentially provides a backdoor mechanism for privilege escalation that bypasses normal authentication mechanisms and could be exploited through various attack vectors including container escape techniques or legitimate administrative access compromise.
The operational impact of this vulnerability extends far beyond individual container compromises, as it enables attackers to establish persistent access to OpenShift clusters and potentially compromise entire application environments. Once an attacker successfully modifies the /etc/passwd file, they can create accounts with uid 0 (root privileges) or modify existing root accounts to gain complete system control. This capability allows for data exfiltration, system manipulation, and the establishment of persistent backdoors within containerized environments. The vulnerability particularly affects organizations using OpenShift Application Platform for application deployment, as it undermines the security assumptions of container isolation and could lead to significant data breaches or service disruption. The impact is further amplified by the fact that the vulnerable container image is commonly used as a base for numerous application builds, potentially affecting hundreds or thousands of deployed applications.
Mitigation strategies for CVE-2019-19348 should focus on immediate version upgrades to patched releases of the openshift/apb-base container image, specifically targeting versions 4.3.5, 4.2.21, 4.1.37, and 3.11.188-4 or later. Organizations should implement strict file permission controls on critical system files within containers, ensuring that /etc/passwd is not writable by non-privileged users and that appropriate access controls are enforced through container runtime security policies. The implementation of container image scanning tools and security monitoring solutions can help detect and prevent exploitation attempts. Additionally, organizations should consider implementing the principle of least privilege for container users, ensuring that containers run with minimal required privileges and that file system access is strictly controlled. This vulnerability also highlights the importance of regular security assessments and patch management processes within containerized environments, as outlined in the MITRE ATT&CK framework's privilege escalation techniques and the broader container security best practices established by industry standards organizations.