porous

adj

1. Full of tiny pores that allow fluids or gasses to pass through.

   “Sponges are porous so they can filter water while trapping food.”

   “Concrete is porous, so water will slowly filter through it.”

2. (figuratively)With many gaps or loopholes.

   “However, Wolves ^([sic]) porous defence opened up again to gift Sunderland a foothold in the game - Sessegnon sweeping in a Zenden corner that was inexplicably allowed to bounce in the six-yard box.”

   “[…] a porous border consequently positioned migrants from Mexico and ethnic Mexicans residing in the United States as potential terrorists.”