Heat the olive oil in a large pot over medium heat. Add the onion, carrots and celery with 1/4 tsp of the salt; cook 7 minutes, stirring, until softened.
Add the garlic and oregano; cook 1 minute, until fragrant.
Add the diced tomatoes with their juices and the vegetable broth. Bring to a simmer and cook 8 minutes.
Stir in the beans, zucchini and pasta; simmer 9-10 minutes more, until the pasta is al dente and the zucchini is tender.
Taste and season with the remaining salt and black pepper. Serve hot.