Typical severity: High. Likelihood of attack: Low. An adversary corrupts or modifies the content of a schema for the purpose of undermining the security of the target. Schemas provide the structure and content definitions for resources used by an application. By replacing or modifying a schema, the adversary can affect how the application handles or interprets a resource, often leading to possible denial of service, entering into an unexpected state, or recording incomplete data.
Design: Protect the schema against unauthorized modification. | Implementation: For applications that use a known schema, use a local copy or a known good repository instead of the schema reference supplied in the schema document. | Implementation: For applications that leverage remote schemas, use the HTTPS protocol to prevent modification of traffic in transit and to avoid unauthorized modification.