427
Structure : Simple
Abstraction : Base
Description
The product does not properly handle input in which an inconsistency exists between two or more
special characters or reserved words.
Extended Description
An example of this problem would be if paired characters appear in the wrong order, or if the
special characters are not properly nested.
Relationships
The table(s) below shows the weaknesses and high level categories that are related to this
weakness. These relationships are defined as ChildOf, ParentOf, MemberOr and give insight to
similar items that may exist at higher and lower levels of abstraction. In addition, relationships such
as PeerOf and CanAlsoBe are defined to show similar weaknesses that may want to be explored.
Relevant to the view "Research Concepts" (CWE-1000)
Nature Type ID Name Page
ChildOf 228 Improper Handling of Syntactically Invalid Structure 568
ChildOf 159 Improper Handling of Invalid Use of Special Elements 411
Relevant to the view "Software Development" (CWE-699)
Nature Type ID Name Page
MemberOf 19 Data Processing Errors 2309
Applicable Platforms
Language : Not Language-Specific (Prevalence = Undetermined)
Common Consequences
Scope Impact Likelihood
Availability
Access Control
Non-Repudiation
DoS: Crash, Exit, or Restart
Bypass Protection Mechanism
Hide Activities
Potential Mitigations
Developers should anticipate that inconsistent special elements will be injected/manipulated in
the input vectors of their product. Use an appropriate combination of denylists and allowlists to
ensure only valid, expected and appropriate input is processed by the system.
Phase: Implementation
Strategy = Input Validation
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.
Phase: Implementation
CWE Version 4.14
CWE-170: Improper Null Termination
CWE-170: Improper Null Termination