Missing permission checks in Jenkins Proxmox Plugin

Jenkins Proxmox Plugin 0.7.0 and earlier does not perform a permission check in several HTTP endpoints, allowing attackers with Overall/Read permission to connect to an attacker-specified host using attacker-specified username and password (perform a connection test), disable SSL/TLS validation for the entire Jenkins controller JVM as part of the connection test (see CVE-2022-28142), and test a rollback with attacker-specified parameters.