Reliance on a Single Factor in a Security Decision |
Weakness ID: 654 (Weakness Base) | Status: Draft |
Description Summary
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 node 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. |
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Scope | Effect |
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Integrity | 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. |
Accountability | 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. |
Example 1
Password-only authentication is perhaps the most well-known example of use of a single factor. Anybody who knows a user's password can impersonate that user.
Example 2
When authenticating, use multiple factors, such as "something you know" (such as a password) and "something you have" (such as a hardware-based one-time password generator, or a biometric device).
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). |
Use redundant access rules on different choke points (e.g., firewalls). |
This node is closely associated with the term "Separation of Privilege." This term is used in several different ways in the industry, but they generally combine two closely related principles: compartmentalization (CWE-653) and using only one factor in a security decision (this node). Proper compartmentalization implicitly introduces multiple factors into a security decision, but there can be cases in which multiple factors are required for authentication or other mechanisms that do not involve compartmentalization, such as performing all required checks on a submitted certificate. It is likely that CWE-653 and CWE-654 will provoke further discussion. |
Ordinality | Description |
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Primary | (where the weakness exists independent of other weaknesses) |
Nature | Type | ID | Name | View(s) this relationship pertains to |
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ChildOf | Category | 254 | Security Features | Development Concepts699 |
ChildOf | Weakness Class | 657 | Violation of Secure Design Principles | Development Concepts (primary)699 Research Concepts (primary)1000 |
ChildOf | Weakness Class | 693 | Protection Mechanism Failure | Research Concepts1000 |
ParentOf | Weakness Base | 308 | Use of Single-factor Authentication | Research Concepts1000 |
ParentOf | Weakness Base | 309 | Use of Password System for Primary Authentication | Research Concepts1000 |
Jerome H. Saltzer and Michael D. Schroeder. "The Protection of Information in Computer Systems". Proceedings of the IEEE 63. September, 1975. <http://web.mit.edu/Saltzer/www/publications/protection/>. |
Sean Barnum and Michael Gegick. "Separation of Privilege". 2005-12-06. <https://buildsecurityin.us-cert.gov/daisy/bsi/articles/knowledge/principles/357.html>. |
Submissions | ||||
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Submission Date | Submitter | Organization | Source | |
2008-01-18 | Pascal Meunier | Purdue University | External Submission | |
Modifications | ||||
Modification Date | Modifier | Organization | Source | |
2008-07-01 | Eric Dalci | Cigital | External | |
updated Time of Introduction | ||||
2008-09-08 | CWE Content Team | MITRE | Internal | |
updated Alternate Terms, Common Consequences, Relationships, Other Notes, Weakness Ordinalities | ||||
2009-01-12 | CWE Content Team | MITRE | Internal | |
updated Description, Name | ||||
2009-05-27 | CWE Content Team | MITRE | Internal | |
updated Relationships | ||||
Previous Entry Names | ||||
Change Date | Previous Entry Name | |||
2009-01-12 | Design Principle Violation: Reliance on a Single Factor in a Security Decision | |||