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.
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."
Demonstrations
The following examples help to illustrate the nature of this weakness and describe methods or techniques which can be used to mitigate the risk.
Note that the examples here are by no means exhaustive and any given weakness may have many subtle varieties, each of which may require different detection methods or runtime controls.
Example One
Switches may revert their functionality to that of hubs when the table used to map ARP information to the switch interface overflows, such as when under a spoofing attack. This results in traffic being broadcast to an eavesdropper, instead of being sent only on the relevant switch interface. To mitigate this type of problem, the developer could limit the number of ARP entries that can be recorded for a given switch interface, while other interfaces may keep functioning normally. Configuration options can be provided on the appropriate actions to be taken in case of a detected failure, but safe defaults should be used.
See Also
Weaknesses in this category are related to violation of secure design principles.
Weaknesses in this category are related to the "IT/OT Convergence/Expansion" category from the SEI ETF "Categories of Security Vulnerabilities in ICS" as published in ...
This category identifies Software Fault Patterns (SFPs) within the Incorrect Exception Behavior cluster (SFP6).
This view (slice) covers all the elements in CWE.
This view (slice) lists weaknesses that can be introduced during implementation.
This view (slice) lists weaknesses that can be introduced during design.
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