Improper Handling of Unexpected Data TypeID: 241 | Date: (C)2012-05-14 (M)2022-10-10 |
Type: weakness | Status: DRAFT |
Abstraction Type: Base |
Description
The software does not handle or incorrectly handles when a
particular element is not the expected type, e.g. it expects a digit (0-9) but
is provided with a letter (A-Z).
Applicable PlatformsLanguage Class: All
Time Of Introduction
- Architecture and Design
- Implementation
Related Attack Patterns
Common Consequences
Scope | Technical Impact | Notes |
---|
IntegrityOther | Varies by contextUnexpected state | |
Detection MethodsNone
Potential Mitigations
Phase | Strategy | Description | Effectiveness | Notes |
---|
Implementation | Input Validation | Assume all input is malicious. Use an "accept known good" input
validation strategy, i.e., use a whitelist 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
(i.e., do not rely on a blacklist). A blacklist 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, blacklists can be useful for detecting potential
attacks or determining which inputs are so malformed that they should be
rejected outright. | | |
Implementation | Input Validation | 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 whitelist validation
schemes by introducing dangerous inputs after they have been
checked. | | |
Relationships
Related CWE | Type | View | Chain |
---|
CWE-241 ChildOf CWE-896 | Category | CWE-888 | |
Demonstrative ExamplesNone
Observed Examples
- CVE-1999-1156 : FTP server crash via PORT command with non-numeric character.
- CVE-2004-0270 : Anti-virus product has assert error when line length is non-numeric.
For more examples, refer to CVE relations in the bottom box.
White Box Definitions None
Black Box Definitions None
Taxynomy Mappings
Taxynomy | Id | Name | Fit |
---|
PLOVER | | Wrong Data Type | |
CERT C Secure Coding | FIO37-C | Do not assume character data has been read | |
CERT C++ Secure Coding | FIO37-CPP | Do not assume character data has been read | |
References:None