Weakness ID: 563
Vulnerability Mapping: ALLOWED This CWE ID may be used to map to real-world vulnerabilitiesAbstraction: Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.
Description
The variable's value is assigned but never used, making it a dead store.
Extended Description
After the assignment, the variable is either assigned another value or goes out of scope. It is likely that the variable is simply vestigial, but it is also possible that the unused variable points out a bug.
Alternate Terms
| Unused Variable |
Common Consequences
This table specifies different individual consequences
associated with the weakness. The Scope identifies the application security area that is
violated, while the Impact describes the negative technical impact that arises if an
adversary succeeds in exploiting this weakness. The Likelihood provides information about
how likely the specific consequence is expected to be seen relative to the other
consequences in the list. For example, there may be high likelihood that a weakness will be
exploited to achieve a certain impact, but a low likelihood that it will be exploited to
achieve a different impact.
| Impact | Details |
|---|---|
|
Quality Degradation; Varies by Context |
Scope: Other
This weakness could be an indication of a bug in the program or a deprecated variable that was not removed and is an indication of poor quality. This could lead to further bugs and the introduction of weaknesses. |
Potential Mitigations
| Phase(s) | Mitigation |
|---|---|
|
Implementation |
Remove unused variables from the code. |
Relationships
This table shows the weaknesses and high level categories that are related to this
weakness. These relationships are defined as ChildOf, ParentOf, MemberOf 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 the user
may want to explore.
Relevant to the view "Research Concepts" (View-1000)
| Nature | Type | ID | Name |
|---|---|---|---|
| ChildOf |
Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.
|
1164 | Irrelevant Code |
Relevant to the view "Software Development" (View-699)
| Nature | Type | ID | Name |
|---|---|---|---|
| MemberOf |
Category - a CWE entry that contains a set of other entries that share a common characteristic.
|
1006 | Bad Coding Practices |
Modes
Of Introduction
The different Modes of Introduction provide information
about how and when this
weakness may be introduced. The Phase identifies a point in the life cycle at which
introduction
may occur, while the Note provides a typical scenario related to introduction during the
given
phase.
| Phase | Note |
|---|---|
| Implementation |
Applicable Platforms
This listing shows possible areas for which the given
weakness could appear. These
may be for specific named Languages, Operating Systems, Architectures, Paradigms,
Technologies,
or a class of such platforms. The platform is listed along with how frequently the given
weakness appears for that instance.
| Languages |
Class: Not Language-Specific (Undetermined Prevalence) |
Demonstrative Examples
Example 1
The following code excerpt assigns to the variable r and then overwrites the value without using it.
(bad code)
Example Language: C
r = getName();
r = getNewBuffer(buf);
Weakness Ordinalities
| Ordinality | Description |
|---|---|
|
Indirect |
(where the weakness is a quality issue that might indirectly make it easier to introduce security-relevant weaknesses or make them more difficult to detect) |
Detection
Methods
| Method | Details |
|---|---|
|
Automated Static Analysis |
Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.) Effectiveness: High |
Memberships
This MemberOf Relationships table shows additional CWE Categories and Views that
reference this weakness as a member. This information is often useful in understanding where a
weakness fits within the context of external information sources.
| Nature | Type | ID | Name |
|---|---|---|---|
| MemberOf | Category - a CWE entry that contains a set of other entries that share a common characteristic. |
747 | CERT C Secure Coding Standard (2008) Chapter 14 - Miscellaneous (MSC) |
| MemberOf | Category - a CWE entry that contains a set of other entries that share a common characteristic. |
883 | CERT C++ Secure Coding Section 49 - Miscellaneous (MSC) |
| MemberOf |  View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). |
884 | CWE Cross-section |
| MemberOf | Category - a CWE entry that contains a set of other entries that share a common characteristic. |
886 | SFP Primary Cluster: Unused entities |
| MemberOf | Category - a CWE entry that contains a set of other entries that share a common characteristic. |
1186 | SEI CERT Perl Coding Standard - Guidelines 50. Miscellaneous (MSC) |
| MemberOf | Category - a CWE entry that contains a set of other entries that share a common characteristic. |
1412 | Comprehensive Categorization: Poor Coding Practices |
Vulnerability Mapping Notes
| Usage |
ALLOWED
(this CWE ID may be used to map to real-world vulnerabilities) |
| Reason | Acceptable-Use |
|
Rationale |
This CWE entry is at the Base level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities. |
|
Comments |
Carefully read both the name and description to ensure that this mapping is an appropriate fit. Do not try to 'force' a mapping to a lower-level Base/Variant simply to comply with this preferred level of abstraction. |
Taxonomy
Mappings
| Mapped Taxonomy Name | Node ID | Fit | Mapped Node Name |
|---|---|---|---|
| CERT C Secure Coding | MSC00-C | Compile cleanly at high warning levels | |
| SEI CERT Perl Coding Standard | MSC01-PL | Imprecise | Detect and remove unused variables |
| Software Fault Patterns | SFP2 | Unused Entities |
Content
History
| Submissions |
|||
|---|---|---|---|
| Submission Date | Submitter | Organization | |
|
2006-07-19
(CWE Draft 3, 2006-07-19) |
Anonymous Tool Vendor (under NDA) | ||
 Modifications |
|||
| Modification Date | Modifier | Organization | |
|
2025-12-11
(CWE 4.19, 2025-12-11) |
CWE Content Team | MITRE | |
| updated Applicable_Platforms | |||
|
2024-02-29
(CWE 4.14, 2024-02-29) |
CWE Content Team | MITRE | |
| updated Demonstrative_Examples | |||
|
2023-06-29
(CWE 4.12, 2023-06-29) |
CWE Content Team | MITRE | |
| updated Mapping_Notes | |||
|
2023-04-27
(CWE 4.11, 2023-04-27) |
CWE Content Team | MITRE | |
| updated Detection_Factors, Relationships, Type | |||
|
2021-03-15
(CWE 4.4, 2021-03-15) |
CWE Content Team | MITRE | |
| updated Relationships | |||
|
2020-02-24
(CWE 4.0, 2020-02-24) |
CWE Content Team | MITRE | |
| updated Relationships | |||
|
2019-01-03
(CWE 3.2, 2019-01-03) |
CWE Content Team | MITRE | |
| updated Relationships, Taxonomy_Mappings, Weakness_Ordinalities | |||
|
2017-11-08
(CWE 3.0, 2017-11-08) |
CWE Content Team | MITRE | |
| updated Alternate_Terms, Name, Relationships, Taxonomy_Mappings | |||
|
2014-07-30
(CWE 2.8, 2014-07-31) |
CWE Content Team | MITRE | |
| updated Taxonomy_Mappings | |||
|
2014-06-23
(CWE 2.7, 2014-06-23) |
CWE Content Team | MITRE | |
| updated Common_Consequences, Description, Name, Other_Notes | |||
|
2012-10-30
(CWE 2.3, 2012-10-30) |
CWE Content Team | MITRE | |
| updated Potential_Mitigations | |||
|
2012-05-11
(CWE 2.2, 2012-05-15) |
CWE Content Team | MITRE | |
| updated Common_Consequences, Relationships | |||
|
2011-09-13
(CWE 2.1, 2011-09-13) |
CWE Content Team | MITRE | |
| updated Relationships, Taxonomy_Mappings | |||
|
2011-06-27
(CWE 2.0, 2011-06-27) |
CWE Content Team | MITRE | |
| updated Common_Consequences | |||
|
2011-06-01
(CWE 1.13, 2011-06-01) |
CWE Content Team | MITRE | |
| updated Common_Consequences | |||
|
2009-05-27
(CWE 1.4, 2009-05-27) |
CWE Content Team | MITRE | |
| updated Demonstrative_Examples | |||
|
2008-11-24
(CWE 1.1, 2008-11-25) |
CWE Content Team | MITRE | |
| updated Relationships, Taxonomy_Mappings | |||
|
2008-09-08
(CWE 1.0, 2008-09-09) |
CWE Content Team | MITRE | |
| updated Description, Relationships, Other_Notes, Taxonomy_Mappings | |||
|
2008-07-01
(CWE 1.0, 2008-09-09) |
Eric Dalci | Cigital | |
| updated Potential_Mitigations, Time_of_Introduction | |||
| Previous Entry Names |
|||
| Change Date | Previous Entry Name | ||
| 2017-11-08 | Assignment to Variable without Use ('Unused Variable') | ||
| 2014-06-23 | Unused Variable | ||