CWE - CWE-128: Wrap-around Error (4.18)

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CWE Glossary Definition

CWE-128: Wrap-around Error

Weakness ID: 128

Vulnerability Mapping: ALLOWED This CWE ID may be used to map to real-world vulnerabilities
Abstraction: 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.

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Description

Wrap around errors occur whenever a value is incremented past the maximum value for its type and therefore "wraps around" to a very small, negative, or undefined value.

Common Consequences

Section HelpThis 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
DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Instability	Scope: Availability This weakness will generally lead to undefined behavior and therefore crashes. In the case of overflows involving loop index variables, the likelihood of infinite loops is also high.
Modify Memory	Scope: Integrity If the value in question is important to data (as opposed to flow), simple data corruption has occurred. Also, if the wrap around results in other conditions such as buffer overflows, further memory corruption may occur.
Execute Unauthorized Code or Commands; Bypass Protection Mechanism	Scope: Confidentiality, Availability, Access Control This weakness can sometimes trigger buffer overflows which can be used to execute arbitrary code. This is usually outside the scope of a program's implicit security policy.

Potential Mitigations

Phase(s)	Mitigation
Requirements specification: The choice could be made to use a language that is not susceptible to these issues.
Architecture and Design	Provide clear upper and lower bounds on the scale of any protocols designed.
Implementation	Perform validation on all incremented variables to ensure that they remain within reasonable bounds.

Relationships

Section Help 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	Pillar Pillar - a weakness that is the most abstract type of weakness and represents a theme for all class/base/variant weaknesses related to it. A Pillar is different from a Category as a Pillar is still technically a type of weakness that describes a mistake, while a Category represents a common characteristic used to group related things.	682	Incorrect Calculation
PeerOf	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.	190	Integer Overflow or Wraparound
CanPrecede	Class 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.	119	Improper Restriction of Operations within the Bounds of a Memory Buffer

Relevant to the view "Software Development" (View-699)

Nature	Type	ID	Name
MemberOf	Category Category - a CWE entry that contains a set of other entries that share a common characteristic.	189	Numeric Errors

Background Details

Due to how addition is performed by computers, if a primitive is incremented past the maximum value possible for its storage space, the system will not recognize this, and therefore increment each bit as if it still had extra space. Because of how negative numbers are represented in binary, primitives interpreted as signed may "wrap" to very large negative values.

Modes Of Introduction

Section HelpThe 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

Section HelpThis 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

C (Often Prevalent)

C++ (Often Prevalent)

Likelihood Of Exploit

Medium

Demonstrative Examples

Example 1

The following image processing code allocates a table for images.

(bad code)

Example Language: C

img_t table_ptr; /*struct containing img data, 10kB each*/
int num_imgs;
...
num_imgs = get_num_imgs();
table_ptr = (img_t*)malloc(sizeof(img_t)*num_imgs);
...

This code intends to allocate a table of size num_imgs, however as num_imgs grows large, the calculation determining the size of the list will eventually overflow (CWE-190). This will result in a very small list to be allocated instead. If the subsequent code operates on the list as if it were num_imgs long, it may result in many types of out-of-bounds problems (CWE-119).

Weakness Ordinalities

Ordinality	Description
Primary	(where the weakness exists independent of other weaknesses)

Memberships

Section HelpThis 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	CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic.	742	CERT C Secure Coding Standard (2008) Chapter 9 - Memory Management (MEM)
MemberOf	CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic.	876	CERT C++ Secure Coding Section 08 - Memory Management (MEM)
MemberOf	CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic.	998	SFP Secondary Cluster: Glitch in Computation
MemberOf	CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic.	1408	Comprehensive Categorization: Incorrect Calculation

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.

Notes

Relationship

The relationship between overflow and wrap-around needs to be examined more closely, since several entries (including CWE-190) are closely related.

Taxonomy Mappings

Mapped Taxonomy Name	Node ID	Fit
CLASP	Wrap-around error
CERT C Secure Coding	MEM07-C	Ensure that the arguments to calloc(), when multiplied, can be represented as a size_t
Software Fault Patterns	SFP1	Glitch in computation

Related Attack Patterns

CAPEC-ID	Attack Pattern Name
CAPEC-92	Forced Integer Overflow

References

[REF-44] Michael Howard, David LeBlanc and John Viega. "24 Deadly Sins of Software Security". "Sin 5: Buffer Overruns." Page 89. McGraw-Hill. 2010.

[REF-62] Mark Dowd, John McDonald and Justin Schuh. "The Art of Software Security Assessment". Chapter 6, "Signed Integer Boundaries", Page 220. 1st Edition. Addison Wesley. 2006.

[REF-18] Secure Software, Inc.. "The CLASP Application Security Process". 2005.
<https://cwe.mitre.org/documents/sources/TheCLASPApplicationSecurityProcess.pdf>. (URL validated: 2024年11月17日)

Content History

Submissions
Submission Date	Submitter	Organization
2006年07月19日 (CWE Draft 3, 2006年07月19日)	CLASP
2006年07月19日 (CWE Draft 3, 2006年07月19日)
Modifications
Modification Date	Modifier	Organization
2023年06月29日	CWE Content Team	MITRE
2023年06月29日	updated Mapping_Notes
2023年04月27日	CWE Content Team	MITRE
2023年04月27日	updated Relationships
2021年03月15日	CWE Content Team	MITRE
2021年03月15日	updated Potential_Mitigations, References
2020年02月24日	CWE Content Team	MITRE
2020年02月24日	updated Relationships
2017年11月08日	CWE Content Team	MITRE
2017年11月08日	updated Causal_Nature, Taxonomy_Mappings
2017年01月19日	CWE Content Team	MITRE
2017年01月19日	updated Relationships
2014年07月30日	CWE Content Team	MITRE
2014年07月30日	updated Relationships, Taxonomy_Mappings
2012年05月11日	CWE Content Team	MITRE
2012年05月11日	updated Common_Consequences, Demonstrative_Examples, References, Relationships
2011年09月13日	CWE Content Team	MITRE
2011年09月13日	updated Relationships, Taxonomy_Mappings
2011年06月01日	CWE Content Team	MITRE
2011年06月01日	updated Common_Consequences
2010年12月13日	CWE Content Team	MITRE
2010年12月13日	updated Background_Details
2009年10月29日	CWE Content Team	MITRE
2009年10月29日	updated Common_Consequences, Relationships
2008年11月24日	CWE Content Team	MITRE
2008年11月24日	updated Relationships, Taxonomy_Mappings
2008年09月08日	CWE Content Team	MITRE
2008年09月08日	updated Applicable_Platforms, Background_Details, Common_Consequences, Relationships, Relationship_Notes, Taxonomy_Mappings, Weakness_Ordinalities

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Page Last Updated: September 09, 2025

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