Podman is a tool for managing OCI containers and pods. From 1.8.1 until 5.8.4, a container image that contains a environment variable with just a key and no value can trick podman into passing that variable from the host into the container. This is made worse by the fact that using an asterisk () will cause podman to pass all host variables into the container. So essentially a malicious image can exfiltrate all podman environment variables that are set in the session from where the container is launched. This vulnerability is fixed in 5.8.4 and 6.0.0.