COMMON WEAKNESS ENUMERATIONDraft

CWE-636

Not Failing Securely ('Failing Open')

When the product encounters an error condition or failure, its design requires it to fall back to a state that is less secure than other options that are available, such as selecting the weakest encryption algorithm or using the most permissive access control restrictions.

Abstraction

Class

Structure

Simple

Likelihood of Exploit

Medium

Understand the problem

What is the problem?

When the product encounters an error condition or failure, its design requires it to fall back to a state that is less secure than other options that are available, such as selecting the weakest encryption algorithm or using the most permissive access control restrictions.

Extended description

By entering a less secure state, the product inherits the weaknesses associated with that state, making it easier to compromise. At the least, it causes administrators to have a false sense of security. This weakness typically occurs as a result of wanting to "fail functional" to minimize administration and support costs, instead of "failing safe."

Terminology

Alternate terms and usages

Failing Open

Root cause

How and when does the problem arise?

Lifecycle phase

Architecture and Design

Lifecycle phase

Implementation

Risk

What does successful exploitation lead to?

Bypass Protection Mechanism

Affected security scopes: Access Control

Intended access restrictions can be bypassed, which is often contradictory to what the product's administrator expects.

Defence

How is it prevented and fixed?

Architecture and Design

Architecture and design approach

Detail
Subdivide and allocate resources and components so that a failure in one part does not affect the entire product.