In Suricata before 6.0.13, an adversary who controls an external source of Lua rules may be able to execute Lua code. This is addressed in 6.0.13 by disabling Lua unless allow-rules is true in the security lua configuration section.
{
    "binaries": [
        {
            "binary_name": "libhtp-0.5.23-1",
            "binary_version": "3.2-2ubuntu3"
        },
        {
            "binary_name": "suricata",
            "binary_version": "3.2-2ubuntu3"
        },
        {
            "binary_name": "suricata-hyperscan",
            "binary_version": "3.2-2ubuntu3"
        },
        {
            "binary_name": "suricata-oinkmaster",
            "binary_version": "3.2-2ubuntu3"
        }
    ]
}