I feel they have problems in all areas. Because if we look at their results, when they score goals they can't defend them, that means the back line is also having problems.
Juventus have the ability to be more than what they are showing now. But somehow they can't show it. Even though they have never lost, but we can see how many points they have lost because of the many draws?
They are in 5th position, so they have to be able to recover quickly, because if not then it is still possible that they will be further away from the top 4.
This season is ridiculous with Juventus because their problems shift from attacking to defense. In earlier of season, when they could not score goals, their defense system worked well. Later of season, when they scored goals, and many goals in some matches, their defense system started to have big issues and can not defend goal advantage for getting three points.
Juventus still have opportunity to enter top four because above clubs are not stable in their performances too. But Juventus must improve their stability, starting with defense and getting more points to catch above clubs. They have to maintain attacking power and avoiding too many conceded goals like latest matches.