With passing games.
Where they're vulnerable is on the ground... maybe that's a stretch too. Opponents averaged a little over 3 yards per carry until Jordan Davis got hurt and it shot up to over 5 for a little. Then Linval Joseph was signed and they were just as good with Joseph as they were with Davis.
Regardless, with the best pair of corners in the league as well as a third corner who leads the league in INTs(despite missing 5 games with injury) and the best pass rush in the NFL by far, QBs have a rough time against the Eagles.