An attacker with access to a minion key can exploit the 'on demand' pillar functionality with a specially crafted git url which could cause and arbitrary command to be run on the master with the same privileges as the master process.
https://docs.saltproject.io/en/3007/topics/releases/3007.4.html
https://docs.saltproject.io/en/3006/topics/releases/3006.12.html