CWE-638

Not Using Complete Mediation

Class

What it is

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.

Impact

Integrity, Confidentiality, Availability, Access Control, Other

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

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.

Real-world CVE examples

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

Related weaknesses

CWE-657 (childof)CWE-862 (childof)

Test & detect

Browse all common weaknesses, check related exploited CVEs, or map to ATT&CK techniques.

Source: MITRE CWE. View on cwe.mitre.org →