CVE-2020-29389

Vulnerability

The official Crux Linux Docker images versions 3.0 through 3.4 contain a blank password for the root user [1]. This means that any container deployed with these images has a root account with no password set, making authentication trivial for anyone who can reach the container's console.

Exploitation

An attacker who can access the container's shell (e.g., via docker exec or SSH if exposed) can simply log in as root with an empty password. No prior authentication or special privileges are required beyond network or console access to the running container.

Impact

Successful exploitation grants the attacker full root privileges within the container. This can lead to complete compromise of the containerized application, data exfiltration, or lateral movement to other containers if misconfigured.

Mitigation

Users should upgrade to Crux Linux Docker image version 3.5 or later, which fixes the blank root password issue [1]. If upgrade is not immediately possible, ensure the container is not exposed to untrusted networks and change the root password immediately after deployment via passwd inside the container.