COMMON WEAKNESS ENUMERATIONDraft

CWE-654

Reliance on a Single Factor in a Security Decision

A protection mechanism relies exclusively, or to a large extent, on the evaluation of a single condition or the integrity of a single object or entity in order to make a decision about granting access to restricted resources or functionality.

Abstraction

Base

Structure

Simple

Likelihood of Exploit

Medium

Understand the problem

What is the problem?

A protection mechanism relies exclusively, or to a large extent, on the evaluation of a single condition or the integrity of a single object or entity in order to make a decision about granting access to restricted resources or functionality.

Terminology

Alternate terms and usages

Separation of Privilege

Some people and publications use the term "Separation of Privilege" to describe this weakness, but this term has dual meanings in current usage. While this entry is closely associated with the original definition of "Separation of Privilege" by Saltzer and Schroeder, others use the same term to describe poor compartmentalization (CWE-653). Because there are multiple interpretations, use of the "Separation of Privilege" term is discouraged.

Root cause

How and when does the problem arise?

Lifecycle phase

Architecture and Design

Lifecycle phase

Implementation

Lifecycle phase

Operation

Risk

What does successful exploitation lead to?

Gain Privileges or Assume Identity

Affected security scopes: Access Control

If the single factor is compromised (e.g. by theft or spoofing), then the integrity of the entire security mechanism can be violated with respect to the user that is identified by that factor.
Hide Activities

Affected security scopes: Non-Repudiation

It can become difficult or impossible for the product to be able to distinguish between legitimate activities by the entity who provided the factor, versus illegitimate activities by an attacker.

Defence

How is it prevented and fixed?

Architecture and Design

Architecture and design approach

Detail
Use multiple simultaneous checks before granting access to critical operations or granting critical privileges. A weaker but helpful mitigation is to use several successive checks (multiple layers of security).

Architecture and Design

Architecture and design approach

Detail
Use redundant access rules on different choke points (e.g., firewalls).
CWE-654: Common Weakness Enumeration Entry CWE-654 · DayBreach Sözlük · DayBreach