From code commit to production takeover

NCC Group performed a pentest in which they had (notionally) compromised a developer's laptop who could commit code to a certain Java library. The researchers set a pre-requirement file to one that provided a Meterpreter shell from within the target build environment. They found themselves on a pod that contained an SSH key that granted access to a Jenkins master node, and proceeded to dump variables. At this point they gained write privileges and cluster admin within the production environment.