Not Using Complete Mediation

Opis

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.

Skutki

• Integrity, Confidentiality, Availability, Access Control, Other

  Gain Privileges or Assume Identity; Execute Unauthorized Code or Commands; Bypass Protection Mechanism; Read Application Data; Other

  A user might retain access to a critical resource even after privileges have been revoked, possibly allowing access to privileged functionality or sensitive information, depending on the role of the resource.

Zapobieganie

• 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.

Przykłady podatności

• CVE-2007-0408 Server does not properly validate client certificates when reusing cached connections.

Słabość nadrzędna

• CWE-657 Violation of Secure Design Principles
• CWE-862 Missing Authorization

Słabości podrzędne

• CWE-424 Improper Protection of Alternate Path

Kiedy powstaje

• Implementation
• Operation

Dotyczy

Not Language-Specific

Źródła

1. The Protection of Information in Computer Systems — Jerome H. Saltzer, Michael D. Schroeder, Proceedings of the IEEE 63, 1975
2. Complete Mediation — Sean Barnum, Michael Gegick, 2005