Glossary M
Mail Server

Mail Server

A host that provides “electronic post office” facilities. It stores incoming mail for distribution to users and forwards outgoing mail. The term may refer to ...

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Malware

Malware

Hardware, firmware, or software that is intentionally included or inserted in a system for a harmful purpose. See IETF RFC 4949 Ver 2 for more information.  A program that ...

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Masquerading

Masquerading

A type of threat action whereby an unauthorized entity gains access to a system or performs a malicious act by illegitimately posing as an authorized ...

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Maximum Tolerable Downtime

Maximum Tolerable Downtime

The amount of time mission/business process can be disrupted without causing significant harm to the organization’s mission. See NIST SP 800-34 Rev. 1 for more information. 

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Media Access Control

Media Access Control

Message Authentication Code. See the following for more information: NIST SP 800-108. NIST SP 800-185. NIST SP 800-56C.  An access control policy that is uniformly enforced across all subjects and ...

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Media Access Control Address

Media Access Control Address

A hardware address that uniquely identifies each component of an IEEE 802-based network. On networks that do not conform to the IEEE 802 standards but ...

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Media Sanitization

Media Sanitization

A general term referring to the actions taken to render data written on media unrecoverable by both ordinary and extraordinary means. See NIST SP 800-88 Rev. 1 under ...

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Message Digest

Message Digest

The result of applying a cryptographic hash function to data (e.g., a message). Also known as a “message digest”. See the following for more information: NIST SP ...

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Metacharacter

Metacharacter

A character that has some special meaning to a computer program and therefore will not be interpreted properly as part of a literal string.See NISTIR ...

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Metadata

Metadata

Information describing the characteristics of data including, for example, structural metadata describing data structures (e.g., data format, syntax, and semantics) and descriptive metadata describing data ...

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Misconfiguration

Misconfiguration

An incorrect or suboptimal configuration of an information system or system component that may lead to vulnerabilities.See NIST SP 800-128 under Misconfiguration for detailed information.A ...

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MITM Attack

MITM Attack

Man in the Middle.An attack using active interception or eavesdropping. It uses a third computer to capture traffic sent between two other systems. See POODLE ...

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Mission Critical

Mission Critical

Any telecommunications or information system that is defined as a national security system (FISMA) or processes any information the loss, misuse, disclosure, or unauthorized access ...

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Mobile Code

Mobile Code

Software programs or parts of programs obtained from remote systems, transmitted across a network, and executed on a local system without explicit installation or execution ...

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