Seems like they are still illegal, the law is just not being enforced (what a shock). The retailer might have a permit, but I doubt if any purchaser has one.
The law states, "§ 10-110. Prohibited acts.
(a) Discharge or possession of fireworks without permit.- Unless the person holds a permit issued under this subtitle, a person may not:
(1) discharge fireworks; or
(2) possess fireworks:
(i) with intent to discharge or allow the discharge of the fireworks in violation of this subtitle; or
(ii) for the purpose of disposing or selling the fireworks to a person for use or discharge without a permit, if a permit is required by this subtitle."
The state definition for fireworks is, "(f) Fireworks.-
(1) "Fireworks" means combustible, implosive or explosive compositions, substances, combinations of substances, or articles that are prepared to produce a visible or audible effect by combustion, explosion, implosion, deflagration, or detonation.
(2) "Fireworks" includes 1.3 G fireworks, 1.4 G fireworks, firecrackers, squibs, rockets, Roman candles, fire balloons, and signal lights.
(3) "Fireworks" does not include:
(i) toy pistols, toy canes, toy guns, or other devices that use paper caps that contain 0.25 grains or less of explosive composition if the devices are constructed so that a hand cannot touch the cap when the cap is in place for use;
(ii) toy pistol paper caps that contain less than 0.20 grains of explosive composition;
(iii) sparklers that do not contain chlorates or perchlorates;
(iv) ground-based sparkling devices that are nonaerial and nonexplosive, and are labeled in accordance with the requirements of the U.S. Consumer Product Safety Commission;
(v) paper wrapped snappers that contain less than 0.03 grains of explosive composition; or
(vi) ash-producing pellets known as "snakes" that do not contain mercury and are not regulated by the U. S. Department of Transportation."