Researchers Discover Alpine Linux Docker Image root User Hard-Coded Credential Vulnerability

Versions of the Official Alpine Linux Docker images (since v3.3) contain a NULL password for the root user. Due to the nature of this issue, systems deployed using affected versions of the Alpine Linux container that utilize Linux PAM, or some other mechanism that uses the system shadow file as an authentication database, may accept a NULL password for the root user. Tested Versions Alpine Docker 3.3 Alpine Docker 3.4 Alpine Docker 3.5 Alpine Docker 3.6 Alpine Docker 3.7 Alpine Docker 3.8 Alpine Docker 3.9 Alpine Docker Edge Product URLs https://hub.docker.com/_/alpine [https://github.com/gliderlabs/docker-alpine/tree/master/][https://github.com/gliderlabs/docker-alpine/tree/master/] CVSSv3 Score 9.8 - CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H CWE CWE-258 - Empty Password in Configuration File Details In builds of the Alpine Docker Image (>=3.3) the /etc/shadow file contains a blank field in place of the encrypted password (sp_pwdp in the context of the spwd struct returned by getspent. $ for i in seq 1 9; do echo -n "date - Alpine Docker 3.$i - "; docker run -it alpine:3.$i head -n 1 /etc/shadow ; done Thu 7 Feb 2019 16:15:43 GMT - Alpine Docker 3.1 - root:!