This Recommendation identifies security threats that may affect safety and security capabilities based on [ITU-T Y.4401]. Firstly@ this Recommendation determines security threats with a possible impact on safety. Secondly@ it identifies which security capabilities can be applied to mitigate these threats. The Internet of things poses specific security challenges@ which may not be covered by existing security objectives (such as confidentiality@ integrity@ availability) completely. Further elaboration of specific security countermeasures relies on an interpretation of security capabilities according to the identified threats. This Recommendation is mostly applicable to safety-critical Internet of things (IoT) systems@ such as industrial automation@ automotive systems@ transportation@ smart cities@ wearable and standalone medical devices@ however it has no specific restrictions and may be used for any domain area of IoT.