A cord lock assembly is configured to selectively tighten and loosen a draw cord of an article. The cord lock assembly may include a shell, a piston and a spring member. The shell defines an interior chamber and includes aligned shell cord passages. The piston is slidably retained within the interior chamber. The piston includes a piston cord passage formed therethrough. The spring member exerts a force into the piston within the shell so that the piston cord passage is misaligned with respect to the shell cord passages in a locked position. A cord may be operatively secured to the piston and may be configured to be pulled to move the piston to align the piston cord passage with the shell cord passages in an unlocked position so that a draw cord may freely pass therethrough.