CVE-2019-19352 in OpenShift
Summary
by MITRE • 03/24/2021
An insecure modification vulnerability in the /etc/passwd file was found in the operator-framework/presto as shipped in Red Hat Openshift 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 • 04/04/2021
The vulnerability identified as CVE-2019-19352 represents a critical privilege escalation flaw within the operator-framework/presto container image distributed with Red Hat OpenShift 4. This issue stems from inadequate file permissions and access controls that allow unauthorized modifications to the system's core authentication file. The /etc/passwd file serves as the primary repository for user account information in Unix-like systems, making its integrity crucial for system security. When an attacker gains access to a container running this vulnerable image, they can exploit the insecure file modification capabilities to alter user account details and potentially gain elevated privileges. This vulnerability directly violates fundamental security principles of least privilege and file system integrity protection.
The technical root cause of this vulnerability lies in the improper configuration of file permissions within the container environment, specifically concerning the /etc/passwd file. According to CWE-732, this represents an inadequate permission assignment where the system fails to properly restrict write access to critical system files. The flaw enables attackers to modify user account information including user IDs, group IDs, and home directories, which can be leveraged to create new administrative accounts or modify existing ones. This insecure modification capability allows threat actors to bypass normal authentication mechanisms and establish persistent access to the system. The vulnerability exists because the container image does not properly isolate the /etc/passwd file from unauthorized modification attempts, creating a direct path for privilege escalation.
The operational impact of CVE-2019-19352 extends beyond simple privilege escalation to encompass potential system compromise and data exfiltration capabilities. Once an attacker successfully modifies the /etc/passwd file, they can gain root-level access to the container and potentially the underlying host system, depending on the container orchestration environment. This vulnerability aligns with ATT&CK technique T1068, which describes the exploitation of elevated privileges through local system exploitation. The attack surface is particularly concerning in containerized environments where containers often run with elevated privileges to perform their functions, making the potential for privilege escalation even more dangerous. Organizations utilizing Red Hat OpenShift 4 with the affected operator-framework/presto image face significant risk of unauthorized access to their containerized applications and underlying infrastructure.
Mitigation strategies for CVE-2019-19352 should focus on implementing proper file system permissions and container security hardening measures. Organizations must ensure that the /etc/passwd file within container images maintains appropriate read-only permissions and that containers are configured with minimal necessary privileges. The remediation approach should include updating to patched versions of the operator-framework/presto image, implementing container runtime security controls, and conducting regular security assessments of container images. Additionally, implementing proper network segmentation and access controls can limit the potential impact of such vulnerabilities. Security teams should also consider implementing file integrity monitoring solutions to detect unauthorized modifications to critical system files and establish proper incident response procedures for handling such security events. This vulnerability demonstrates the critical importance of maintaining secure container configurations and proper file system access controls in modern cloud-native environments.