MP.L2-3.8.8 Shared Media

CMMC Practice MP.L2-3.8.8 – Shared Media: Prohibit the use of portable storage devices when such devices have no identifiable owner.

Links to Publicly Available Resources

Discussion [NIST SP 800-171 R2]
Requiring identifiable owners (e.g., individuals, organizations, or projects) for portable storage devices reduces the overall risk of using such technologies by allowing organizations to assign responsibility and accountability for addressing known vulnerabilities in the devices (e.g., insertion of malicious code).

Further Discussion
A portable storage device is a system component that can be inserted into and removed from a system and is used to store data or information. It typically plugs into a laptop or desktop port (e.g., USB port). These devices can contain malicious files that can lead to a compromise of a connected system. Therefore, use should be prohibited if the device cannot be traced to an owner who is responsible and accountable for its security.
This practice, MP.L2-3.8.8, furthers the protections provided by MP.L2-3.8.7 by prohibiting unidentified media use even if that media type is allowable.