Well it depends on how the over-extending is done. If it is a gradual space advantage that is supported over the course of the game like Karpov's infamous squeezing, then it is very difficult to survive, but the defender has a few resources such as exchanging pieces so their cramped forces have more room to move. However...
I seriously doubt that complicated subject is what you mean by "overextending" here. I imagine you are referring to something very common sub 1200 rating and that is lots of pawn pushing. If you aren't careful, it is tough to defend against the huge mass of pawns marching towards you. Luckily, there is an antidote that you can use and learn with some practice.
Against these pawn-pushing players, we must analyze what the weakness of their play-style is. That weakness is moving too many pawns. All of the pieces in chess can move backwards to the square they just came from except for the pawns. Chess pawns can't ever go back, so a good chess player is careful about advancing any pawns since they can no longer influence squares they pass already.
Another draw-back to these pawn pushing ideas is the fact that the player is not following development of chess opening principles. This means that if they move pawns a lot, then you have the chance to get ahead in development by moving your pieces (Knights, Bishops, Rooks, Queen or King such as castling).
For these I recommend using chess opening principles if you can. This is always true, but especially if the opponent isn't developing pieces.
https://www.chess.com/blog/KeSetoKaiba/opening-principles-again
The other recommendation is seeing if you can "infiltrate" your pieces behind their pawns because again pawns can't move backwards. It will be annoying for your opponent to try to kick back your pieces if can't be moved by pawns since you got behind them already 
Recently I have noticed something about people at my level. they love to just chase pieces, and chase pieces, and chase pieces with pawns, until their pawn structure is very overextended quite early in the game. but I have been finding it increasingly difficult to punish this kind of pawn play. I know it is an unsound way to play, but with this make-a-threat-on-every-move-with-pawns strategy, I find it very hard to create counterplay, or to open the position at all. how do you punish this kind of play?