Description
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.
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."
Potential Impact
Access Control
Bypass Protection Mechanism
Mitigations & Prevention
Subdivide and allocate resources and components so that a failure in one part does not affect the entire product.
Real-World CVE Examples
| CVE ID | Description |
|---|---|
| CVE-2007-5277 | The failure of connection attempts in a web browser resets DNS pin restrictions. An attacker can then bypass the same origin policy by rebinding a domain name to a different IP address. This was an at |
| CVE-2006-4407 | Incorrect prioritization leads to the selection of a weaker cipher. Although it is not known whether this issue occurred in implementation or design, it is feasible that a poorly designed algorithm co |
Related Weaknesses
Taxonomy Mappings
- OWASP Top Ten 2004: A7 — Improper Error Handling
Frequently Asked Questions
What is CWE-636?
CWE-636 (Not Failing Securely ('Failing Open')) is a software weakness identified by MITRE's Common Weakness Enumeration. It is classified as a Class-level weakness. 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 encry...
How can CWE-636 be exploited?
Attackers can exploit CWE-636 (Not Failing Securely ('Failing Open')) to bypass protection mechanism. This weakness is typically introduced during the Architecture and Design, Implementation phase of software development.
How do I prevent CWE-636?
Key mitigations include: Subdivide and allocate resources and components so that a failure in one part does not affect the entire product.
What is the severity of CWE-636?
CWE-636 is classified as a Class-level weakness (High abstraction). It has been observed in 2 real-world CVEs.