CWE-178
Improper Handling of Case Sensitivity
AI Translation Available
The product does not properly account for differences in case sensitivity when accessing or determining the properties of a resource, leading to inconsistent results.
Status
incomplete
Abstraction
base
Affected Platforms
Windows
macOS
Extended Description
AI Translation
Improperly handled case sensitive data can lead to several possible consequences, including:
- case-insensitive passwords reducing the size of the key space, making brute force attacks easier
- bypassing filters or access controls using alternate names
- multiple interpretation errors using alternate names.
Technical Details
AI Translation
Common Consequences
access control
Impacts
bypass protection mechanism
Potential Mitigations
Phases:
architecture and design
implementation
Descriptions:
•
Avoid making decisions based on names of resources (e.g. files) if those resources can have alternate names.
•
Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked.
•
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue."
Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
Functional Areas
file processing