This can be a tricky one to answer, you don’t want to come across as too ambitious just yet because you are presumably just trying to land you’re first or second security position. At the same time you don’t want to come off as desperate because it will look bad but also because the company you are working for might just be looking for career minded people for more senior roles in the future.

Say something like “First of all my main priority is to get a clearer understanding of the security sector, and then as my knowledge and understanding grows i would like to take on more senior positions so that i can impart my knowledge and skills onto others and also so i can become a more valuable asset to the company”. This will show your interviewer that you know that nothing comes without hard work and that you are willing to prove yourself to the company.