Such a tricky question.the interviewer ask this question to reaveal your shortcomings,but if you use the right way to way then it can be a golden opportunity to show that you are right for the job.You just need to show yourself in the best possible way.Think about it in advance and you'll be able to answer this question smartly that helps you to come across in a positive light.And Try to turn a negative into a positive.Take a look on some examples:

☛ You are too much of a perfectionist.

☛ You work too hard sometimes.

☛ You are too detailed person(spending time on every single point).ETC

Just don't be too honest here.