Aircrafts are designed to take lightning strikes. The outer fuselage acts as a Faraday cage. Usual entry points are the front (dome), forward fuselage and the wing tips. Because the modern aircraft is made of composites, the manufacturers use wire mesh, aluminium flame spray coatings , embedded metallic wires etc to allow the lightning to flow.
Also the probability of lightning falls dramatically above 20,000ft. Aircraft fly far above this limit and hence the lightning danger is mainly during the ascent and descent, when the aircraft is between 5000 - 15000 ft and obviously weather dependent.
Only a few accidents have taken place, the last probably was an Aeroflot, somewhere last year suspected of a lightning hit while on the ascent.