ATTACKING GITLAB CI/CD VIA SHARED RUNNERS

Summary from the TLDR InfoSec newsletter

A post from Pulse Security that examines ways that a compromised pipeline running on a GitLab shared runner can be used to escape from its isolation, compromise the shared runner, and then compromise any other jobs on that runner. The post specifically focuses on the docker-in-docker executor on GitLab, but many of the techniques described can be generalized.