Oracle Linux: CVE-2019-13139: ELSA-2019-4813: docker-engine security update (IMPORTANT)

In Docker before 18.09.4, an attacker who is capable of supplying or manipulating the build path for the "docker build" command would be able to gain command execution. An issue exists in the way "docker build" processes remote git URLs, and results in command injection into the underlying "git clone" command, leading to code execution in the context of the user executing the "docker build" command. This occurs because git ref can be misinterpreted as a flag.
A command injection flaw was discovered in Docker during the `docker build` command. By providing a specially crafted path argument for the container to build, it is possible to inject command options to the `git fetch`/`git checkout` commands that are executed by Docker and to execute code with the privileges of the user running Docker. A local attacker who can run `docker build` with a controlled build path, or a remote attacker who has control over the docker build path, could elevate their privileges or execute code.