CWE-194 - Unexpected Sign Extension
- Abstraction:Variant
- Structure:Simple
- Status:Incomplete
- Release Date:2006-07-19
- Latest Modification Date:2025-12-11
Weakness Name
Unexpected Sign Extension
Description
The product performs an operation on a number that causes it to be sign extended when it is transformed into a larger data type. When the original number is negative, this can produce unexpected values that lead to resultant weaknesses.
Common Consequences
Scope: Integrity, Confidentiality, Availability, Other
Impact: Read Memory, Modify Memory, Other
Notes: When an unexpected sign extension occurs in code that operates directly on memory buffers, such as a size value or a memory index, then it could cause the program to write or read outside the boundaries of the intended buffer. If the numeric value is associated with an application-level resource, such as a quantity or price for a product in an e-commerce site, then the sign extension could produce a value that is much higher (or lower) than the application's allowable range.