CVE-2019-5021 Explained : Impact and Mitigation

Alpine Linux Docker images starting from version 3.3 have a security vulnerability where the

root

user has a NULL password.

Understanding CVE-2019-5021

The Official Alpine Linux Docker images, from version 3.3 onwards, are affected by a security weakness that allows the

root

user to have a NULL password.

What is CVE-2019-5021?

This vulnerability stems from a mistake made in December 2015, potentially enabling a NULL password for the

root

user on systems using affected versions of Alpine Linux containers.

The Impact of CVE-2019-5021

CVSS Base Score: 9.8 (Critical)
Attack Vector: Network
Attack Complexity: Low
Confidentiality Impact: High
Integrity Impact: High
Availability Impact: High

Technical Details of CVE-2019-5021

Alpine Linux Docker images are affected by a security weakness that allows the

root

user to have a NULL password.

Vulnerability Description

The vulnerability in Alpine Linux Docker images allows the

root

user to have a NULL password, originating from a regression in December 2015.

Affected Systems and Versions

Affected Versions: Alpine Docker 3.3 to Alpine Docker Edge

Exploitation Mechanism

Systems using affected versions of Alpine Linux containers and relying on Linux PAM or similar methods may accept a NULL password for the

root

user.

Mitigation and Prevention

Immediate action and long-term security practices are crucial to mitigate the impact of CVE-2019-5021.

Immediate Steps to Take

Update to non-vulnerable versions of Alpine Linux Docker images.
Implement strong password policies for all users.
Monitor and restrict network access to affected systems.

Long-Term Security Practices

Regularly update and patch container images.
Conduct security audits and vulnerability assessments.

Patching and Updates

Apply patches provided by Alpine Linux to address the vulnerability.