In plain terms. The Digital Millennium Copyright Act criminalizes circumvention of technological measures that control access to copyrighted works and provides safe harbors for online service providers. Its anti-circumvention provisions—and the Librarian of Congress's periodic security-research exemptions—directly affect the legality of vulnerability research and reverse engineering.
Citation. Pub. L. 105-304 (Oct. 28, 1998); 17 U.S.C. §§ 512, 1201-1205.