  Modern vehicular wireless technology enables vehicles to exchange information
at any time, from any place, to any network -- forms the vehicle-to-everything
(V2X) communication platforms. Despite benefits, V2X applications also face
great challenges to security and privacy -- a very valid concern since breaches
are not uncommon in automotive communication networks and applications. In this
survey, we provide an extensive overview of V2X ecosystem. We also review main
security/privacy issues, current standardization activities and existing
defense mechanisms proposed within the V2X domain. We then identified semantic
gaps of existing security solutions and outline possible open issues.
