COMMON WEAKNESS ENUMERATIONDraft

CWE-370

Missing Check for Certificate Revocation after Initial Check

The product does not check the revocation status of a certificate after its initial revocation check, which can cause the product to perform privileged actions even after the certificate is revoked at a later time.

Abstraction

Variant

Structure

Simple

Likelihood of Exploit

Medium

Understand the problem

What is the problem?

The product does not check the revocation status of a certificate after its initial revocation check, which can cause the product to perform privileged actions even after the certificate is revoked at a later time.

Extended description

If the revocation status of a certificate is not checked before each action that requires privileges, the system may be subject to a race condition. If a certificate is revoked after the initial check, all subsequent actions taken with the owner of the revoked certificate will lose all benefits guaranteed by the certificate. In fact, it is almost certain that the use of a revoked certificate indicates malicious activity.

Root cause

How and when does the problem arise?

Lifecycle phase

Implementation

Risk

What does successful exploitation lead to?

Gain Privileges or Assume Identity

Affected security scopes: Access Control

Trust may be assigned to an entity who is not who it claims to be.
Modify Application Data

Affected security scopes: Integrity

Data from an untrusted (and possibly malicious) source may be integrated.
Read Application Data

Affected security scopes: Confidentiality

Data may be disclosed to an entity impersonating a trusted entity, resulting in information disclosure.

Defence

How is it prevented and fixed?

Architecture and Design

Architecture and design approach

Detail
Ensure that certificates are checked for revoked status before each use of a protected resource. If the certificate is checked before each access of a protected resource, the delay subject to a possible race condition becomes almost negligible and significantly reduces the risk associated with this issue.