Humble employee is a good employee. You should feel free to talk about your weaknesses in an interview. After all, interviewer is aware of it, doesn't matter if you talk about it or not… Therefore, try to be honest. But do not stop there. Elaborate on your answer, explaining what you do to improve on your weakness. That is an attitude of a responsible assistant, an attitude all interviewers seek in the applicants.

We all have weaknesses… But just some of us are able to admit it and do something to improve on it.