Abertura

n. opening, aperture; gap; slit, crack; cove; pass, narrow road between mountains; (Figurative) openness, quality of being open, frankness

n. opening, access, aperture, crevice, gap, window, slot, hole, openness; overture; rift, slit, vent, loophole, candor, bay, stoma

v. hold by the collar to attack

= chink, opening.
Ex: War of words exposed chinks in coalition.
Ex: The cyber criminals are persistent -- if they can't get through one opening, they will keep trying until they find the chink in the armour.