In an upgraded v14.2 we faced the same issue than jayant.moosad, and checkin at "Processes", process-name, "Access to this Process", there is rights for nobody but administrator.
However, processes can be started :
-from an event generated by a user with Global right: "Process - Start - All" but without "Process - AutoStart - All"
-from an event generated by a user with the Global right: "Process View Instance - All" but without "Process - AutoStart - All" or "Process - Start - All"
-some processes appears as initiated by Niku Administrator instead of the username (and curiously these are the processes with many steps)
It doesn't seems a general failure of v14.2 because in a fresh installation previous behavior is not reproducible,
jayant.moosad What clarity version are you using? did you upgrade Clarity from an old version? had you this behavior before?