CVE-2019-19355 in openshift
Summary
by MITRE
An insecure modification vulnerability in the /etc/passwd file was found in the openshift/ocp-release-operator-sdk. An attacker with access to the container could use this flaw to modify /etc/passwd and escalate their privileges. This CVE is specific to the openshift/ansible-operator-container as shipped in Openshift 4.
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Analysis
by VulDB Data Team • 04/17/2024
The vulnerability identified as CVE-2019-19355 represents a critical privilege escalation flaw within the OpenShift containerized operator environment. This issue specifically affects the openshift/ansible-operator-container component that is integral to OpenShift 4 deployments, where the operator-sdk framework fails to properly secure file modifications to the system password database. The flaw stems from inadequate access controls and file system permissions that allow unauthorized modification of the /etc/passwd file, a fundamental system component that stores user account information and password hashes.
The technical implementation of this vulnerability exposes a direct path for privilege escalation through insecure file modification practices. When an attacker gains access to the container runtime environment, they can manipulate the /etc/passwd file to add new user accounts with elevated privileges or modify existing user permissions. This represents a classic insecure modification vulnerability classified under CWE-276, which deals with incorrect permissions for critical resources. The flaw specifically targets the containerized operator environment where the ansible-operator-container executes privileged operations, making it particularly dangerous in multi-tenant cloud deployments where container isolation is expected.
The operational impact of this vulnerability extends beyond simple privilege escalation to compromise the entire container orchestration environment. Attackers can leverage this flaw to establish persistent access within OpenShift clusters, potentially moving laterally across multiple containers and services. The vulnerability affects the core security model of OpenShift 4 where containerized operators are expected to operate with strict isolation boundaries. This weakness undermines the principle of least privilege and can lead to complete cluster compromise, as demonstrated by the ATT&CK framework's privilege escalation techniques that exploit similar file system modification vulnerabilities to gain administrative control.
Mitigation strategies for CVE-2019-19355 require immediate implementation of enhanced container security measures and proper file system access controls. Organizations should implement read-only file systems for critical system files including /etc/passwd, enforce strict container runtime security policies, and utilize OpenShift's built-in security features such as pod security policies and mandatory access controls. The solution involves configuring containers with minimal necessary permissions, implementing proper file system mount options, and ensuring that operator containers do not run with unnecessary elevated privileges. Additionally, regular security scanning of container images and implementing continuous monitoring for unauthorized file modifications can help detect exploitation attempts. The vulnerability highlights the importance of proper container security hardening and demonstrates how seemingly simple file system access controls can have catastrophic security implications in cloud-native environments.