DSST Cybersecurity key terms

A principle stating that each user, process, or service should receive only the minimum access rights needed to perform its assigned task, and only for as long as required.

A control that divides a sensitive task among multiple people so no single individual can complete a fraudulent or damaging action alone, such as splitting request, approval, and payment.

An authorization model that grants permissions to job roles rather than to individuals, so users inherit rights by assignment to a role and access is easier to audit and revoke.

An authorization model that evaluates attributes of the user, resource, action, and environment against policy rules, enabling fine-grained, context-aware decisions such as time-of-day or device posture.

An access model where the system enforces labels and clearances assigned by an administrator, and users cannot change or delegate those labels themselves; common in high-assurance and government environments.

An access model in which the owner of a resource decides who else may access it and with what permissions, typically implemented through file permissions and access control lists.

An attached list on a resource that names which users or groups are allowed or denied specific operations, evaluated in order to decide whether a request succeeds.

Authentication that requires two or more independent credential types from different categories, such as a password plus a one-time code, so a stolen password alone is insufficient to log in.

A design where one authentication event establishes a session usable across multiple applications, reducing password fatigue while concentrating risk on the identity provider and its session tokens.

A trust arrangement in which separate organizations or systems accept each other's authentication assertions, letting users access partner resources with credentials issued by their home identity provider.

An XML-based standard for exchanging authentication and authorization assertions between an identity provider and a service provider, widely used for browser-based enterprise single sign-on.

An identity layer built on OAuth 2.0 that issues a signed identity token describing the authenticated user, commonly used for web and mobile login and API access.

A framework for delegated authorization in which a user grants a client application limited, scoped access to a resource without sharing the password; it is not itself an authentication protocol.

A ticket-based network authentication protocol in which a trusted key distribution center issues time-limited tickets that let clients prove identity to services without resending passwords.

A credential valid for a single login or short interval, generated by a hardware token or authenticator app using a shared secret and a counter or clock value.

A hardware authenticator implementing public-key cryptography that binds credentials to a specific origin, resisting phishing because it will not release a credential to an impostor site.

An attack that replays username and password pairs leaked from one breach against other services, succeeding wherever users reused the same password across sites.

A low-and-slow attack that tries one or a few common passwords against many accounts to avoid triggering lockout thresholds, exploiting weak password policy rather than a single cracked secret.

A policy that temporarily disables sign-in after a set number of failed attempts, slowing online guessing while creating a denial-of-service risk if attackers deliberately lock known usernames.

An attack in which an adversary steals or predicts a valid session token and uses it to impersonate an authenticated user, bypassing the login step entirely.

An access credential that grants its holder the associated rights with no further proof of identity, so interception or leakage is equivalent to handing over the session.

A web flaw where untrusted input is rendered as executable script in another user's browser, enabling theft of cookies and tokens or actions performed as the victim.

An attack that tricks a logged-in user's browser into sending an authenticated state-changing request to a vulnerable site, which trusts the ambient session cookie.

An attack that inserts crafted syntax into input so it alters a database query, potentially exposing, modifying, or deleting records; prevented by parameterized queries and strict input handling.

Checking that data entering a system matches expected type, length, format, and range, rejecting anything else; a primary defense that reduces injection, overflow, and malformed-request attacks.

A database query template in which user-supplied values are bound as parameters rather than concatenated into SQL text, structurally preventing injection through those values.

A memory-safety defect where a program writes beyond an allocated buffer, corrupting adjacent data and potentially allowing an attacker to redirect execution.

An operating-system hardening technique that randomizes memory locations of code and data at load time, making it harder for an exploit to jump to a known target address.

A cookie attribute that limits whether the browser sends the cookie on cross-site requests, reducing cross-site request forgery exposure when set to Lax or Strict.

The disciplined process of identifying, testing, deploying, and verifying software updates so known vulnerabilities are closed before attackers can exploit them.

Automated probing of hosts and applications against known signatures and configuration checks to produce a list of suspected weaknesses for triage and remediation.

An authorized, goal-directed simulation of an attacker that chains weaknesses together to demonstrate real business impact, going beyond what a scanner can report.

A written agreement defining the scope, timing, permitted techniques, contacts, and escalation path for a security test, protecting both the tester and the organization.

A public catalog that assigns a unique identifier to each disclosed vulnerability, giving vendors and tools a shared name for the same flaw.

An open framework producing a numeric severity score from characteristics such as attack vector, complexity, privileges required, and impact, used to prioritize remediation.

A documented management decision to tolerate an identified risk without further treatment, typically because the cost of mitigation exceeds the potential loss or the exposure is temporary.

The risk that remains after existing controls and planned treatments have been applied; it must be communicated to and owned by management rather than assumed to be zero.

A study identifying critical business functions and quantifying the effect of their disruption over time, producing recovery priorities and targets that drive continuity planning.

The maximum acceptable amount of data loss measured in time, which determines how frequently backups or replication must occur for a given system.

The maximum acceptable elapsed time to restore a function after disruption, setting the urgency and architecture of recovery arrangements for that system.

A documented, unbroken record of who handled evidence, when, and for what purpose, preserving its integrity so it remains admissible and credible in proceedings.

The practice of collecting the most perishable evidence first, such as memory and network state, before slower-changing disk data, because it disappears on shutdown or reboot.

A documented set of roles, phases, and communication paths for detecting, containing, eradicating, and recovering from security incidents, exercised before a real event occurs.

A network segment between the internet and the internal network that hosts externally reachable services, limiting what an attacker can reach after compromising a public-facing host.

Dividing a network into zones with enforced boundaries so traffic between them is filtered, containing lateral movement and limiting the blast radius of a compromise.

A packet filter that tracks connection state and permits return traffic for sessions it observed, rather than judging each packet in isolation.

An encrypted tunnel that carries traffic between a remote device or site and a trusted network, protecting confidentiality on untrusted paths such as public Wi-Fi.

A protocol that encrypts and authenticates data in transit between client and server using certificates and negotiated session keys, underpinning HTTPS and many other services.

A trusted entity that verifies identity and digitally signs public-key certificates, allowing relying parties to confirm they are communicating with the intended party.

The policies, roles, and systems used to issue, distribute, validate, renew, and revoke certificates, binding public keys to verified identities.

A signed list published by a certificate authority naming certificates that must no longer be trusted, checked by relying parties before accepting a certificate.

An attack that captures a valid authentication exchange or message and resends it later to gain access or repeat an action, defeated by timestamps, nonces, and short-lived tokens.

An attack in which an adversary secretly relays or alters traffic between two parties who believe they are communicating directly, often enabled by unvalidated certificates or rogue access points.

A physical intrusion technique in which an unauthorized person follows an authorized individual through a controlled door without presenting credentials, exploiting courtesy or inattention.

A small enclosed space with two interlocking doors that admits one person at a time, preventing tailgating and providing a controlled checkpoint into a secured area.

Procedures for signing in guests, issuing badges, escorting them in sensitive areas, and logging their departure, so unknown persons cannot move freely through a facility.