Gianluca Varisco presented on security issues related to DevOps infrastructure. He discussed potential exposures in tools like GitHub, revision control systems, continuous integration tools like Jenkins, AWS configuration files, client provisioning tools, Elasticsearch, Redis, and Memcache. Some key risks included exposing private source code repositories, misconfigured systems with default credentials, and services listening on public interfaces without authentication. He emphasized the importance of access control, updating software, changing default keys, and firewall configuration.