STRIDE

STRIDE is a threat-modeling framework used to systematically identify security threats in an application, API, or cloud architecture. Each letter represents a type of threat and the security property it can violate.

Threat	Meaning	Example	Typical controls
S — Spoofing	Pretending to be another user, service, or system	An attacker uses a stolen OAuth token to impersonate a user	MFA, strong authentication, token validation, certificate-based identity
T — Tampering	Unauthorized modification of data or code	Changing an API request, database record, or message in transit	TLS, digital signatures, integrity checks, authorization, immutable logs
R — Repudiation	Denying an action when there is insufficient evidence to prove who performed it	A user denies approving a financial transaction	Centralized audit logs, timestamps, correlation IDs, signed events
I — Information Disclosure	Exposing information to an unauthorized party	An API returns another tenant’s customer records	Encryption, access control, tenant isolation, data masking, least privilege
D — Denial of Service	Making a system or resource unavailable	Flooding an API until legitimate requests fail	Rate limiting, WAF, autoscaling, caching, DDoS protection, circuit breakers
E — Elevation of Privilege	Gaining permissions beyond those authorized	A normal user accesses an admin endpoint by changing a role claim	RBAC/ABAC, server-side authorization, least privilege, privilege separation

Security-property mapping
A useful way to remember the model is:

• Spoofing → Authentication
• Tampering → Integrity
• Repudiation → Non-repudiation
• Information disclosure → Confidentiality
• Denial of service → Availability
• Elevation of privilege → Authorization

Example: API threat model
For a multi-tenant API:

• Spoofing: a forged or stolen JWT is accepted.
• Tampering: a client changes tenantId in the request body.
• Repudiation: administrative actions are not recorded with the actor’s identity.
• Information disclosure: a user queries records belonging to another tenant.
• Denial of service: one tenant consumes all API capacity.
• Elevation of privilege: a regular user sets role=admin in a request.

STRIDE is normally applied to a data-flow diagram by examining processes, data stores, data flows, external entities, and trust boundaries, then asking which STRIDE categories apply to each component.