intrusion
An unauthorized act of bypassing the security mechanisms of a network or information system.
Senses
Sense 1
An unauthorized act of bypassing the security mechanisms of a network or information system.
- NICCS (CISA) Cybersecurity VocabularyJan 06, 2026NICCS glossary export (CSV)https://niccs.cisa.gov/rest/vocab/export-csvNICCS is a CISA (DHS) program. Individual glossary entries include a "From" attribution (e.g., CNSSI 4009, NIST SPs, NICE Framework). Treat "From" values as upstream provenance and verify before quoting large portions of text.Source: NICCS (CISA) Cybersecurity Vocabulary (niccs.cisa.gov).
1 (I)
A security event, or a combination of multiple security events, that constitutes a security incident in which an intruder gains, or attempts to gain, access to a system or system resource without having authorization to do so. (See: IDS.)
- IETF RFC 4949 (Internet Security Glossary)Jan 06, 2026RFC 4949 — Internet Security Glossary (Version 2)https://www.rfc-editor.org/rfc/rfc4949.txtRFC 4949 is published by the IETF Trust and marked as "Distribution of this memo is unlimited". Verify IETF Trust copyright/licensing terms for reuse.Source: IETF RFC 4949 (rfc-editor.org).
2 (I)
A type of threat action whereby an unauthorized entity gains access to sensitive data by circumventing a system's security protections. (See: unauthorized disclosure.)
Usage: This type of threat action includes the following subtypes:
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"Trespass": Gaining physical access to sensitive data by circumventing a system's protections.
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"Penetration": Gaining logical access to sensitive data by circumventing a system's protections.
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"Reverse engineering": Acquiring sensitive data by disassembling and analyzing the design of a system component.
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"Cryptanalysis": Transforming encrypted data into plain text without having prior knowledge of encryption parameters or processes. (See: main entry for "cryptanalysis".)
- IETF RFC 4949 (Internet Security Glossary)Jan 06, 2026RFC 4949 — Internet Security Glossary (Version 2)https://www.rfc-editor.org/rfc/rfc4949.txtRFC 4949 is published by the IETF Trust and marked as "Distribution of this memo is unlimited". Verify IETF Trust copyright/licensing terms for reuse.Source: IETF RFC 4949 (rfc-editor.org).