Cook the pasta according to the instructions on the package in plenty of water with some salt 'al dente'. Drain and rinse with cold water.
In the meantime, finely chop the onion, cut the cucumber lengthwise into six and then into pieces and the tomatoes into quarters. Let the corn drain
Then toss the pasta with the vegetables. Season the salad with lemon juice, finely grated (cleanly scrubbed) lemon zest, and salt and pepper.