CWE-638Not Using Complete Mediation

Description

The product does not perform access checks on a resource every time the resource is accessed by an entity, which can create resultant weaknesses if that entity's rights or privileges change over time.

Common consequences

• Integrity,Confidentiality,Availability,Access Control,Other→Gain Privileges or Assume Identity,Execute Unauthorized Code or Commands,Bypass Protection Mechanism,Read Application Da
  A user might retain access to a critical resource even after privileges have been revoked, possibly allowing access to privileged functionality or sensitive information, depending on the role of the resource.

Potential mitigations

• Architecture and Design
  Invalidate cached privileges, file handles or descriptors, or other access credentials whenever identities, processes, policies, roles, capabilities or permissions change. Perform complete authentication checks before accepting, caching and reusing data, dynamic content and code (scripts). Avoid caching access control decisions as much as possible.
• Architecture and Design
  Identify all possible code paths that might access sensitive resources. If possible, create and use a single interface that performs the access checks, and develop code standards that require use of this interface.

Related CWEs