Not Failing Securely ('Failing Open')

Opis

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."

Inne nazwy

Failing Open

Skutki

• Access Control

  Bypass Protection Mechanism

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

Zapobieganie

• Architecture and Design

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

Przykłady podatności

• 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 attempt to "fail functional."
• 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 could be a factor.

Słabość nadrzędna

• CWE-657 Violation of Secure Design Principles
• CWE-755 Improper Handling of Exceptional Conditions

Pokrewna

• CWE-280 Improper Handling of Insufficient Permissions or Privileges

Słabości podrzędne

• CWE-455 Non-exit on Failed Initialization

Kiedy powstaje

• Architecture and Design
• Implementation

Dotyczy

Not Language-Specific, Not Technology-Specific, ICS/OT

Uwagi

Since design issues are hard to fix, they are rarely publicly reported, so there are few CVE examples of this problem as of January 2008. Most publicly reported issues occur as the result of an implementation error instead of design, such as CVE-2005-3177 (Improper handling of large numbers of resources) or CVE-2005-2969 (inadvertently disabling a verification step, leading to selection of a weaker protocol).

Źródła

1. The Protection of Information in Computer Systems — Jerome H. Saltzer, Michael D. Schroeder, Proceedings of the IEEE 63, 1975
2. Failing Securely — Sean Barnum, Michael Gegick, 2005