The product performs a calculation that can
produce an integer overflow or wraparound when the logic
assumes that the resulting value will always be larger than
the original value. This occurs when an integer value is
incremented to a value that is too large to store in the
associated representation. When this occurs, the value may
become a very small or negative number.

Primary

Resultant

Overflow
The terms "overflow" and "wraparound" are
used interchangeably by some people, but they can have
more precise distinctions by others. See Terminology
Notes.

Wraparound
The terms "overflow" and "wraparound" are
used interchangeably by some people, but they can have
more precise distinctions by others. See Terminology
Notes.

wrap, wrap-around, wrap around
Alternate spellings of "wraparound"

Implementation
This weakness may become security critical when determining the offset or size in behaviors such as memory allocation, copying, and concatenation.

Medium

Availability
DoS: Crash, Exit, or Restart
DoS: Resource Consumption (Memory)
DoS: Instability
This weakness can generally lead to undefined behavior and therefore crashes. When the calculated result is used for resource allocation, this weakness can cause too many (or too few) resources to be allocated, possibly enabling crashes if the product requests more resources than can be provided.

Integrity
Modify Memory
If the value in question is important to data (as opposed to flow), simple data corruption has occurred. Also, if the overflow/wraparound results in other conditions such as buffer overflows, further memory corruption may occur.

Confidentiality
Availability
Access Control
Execute Unauthorized Code or Commands
Bypass Protection Mechanism
This weakness can sometimes trigger buffer overflows, which can be used to execute arbitrary code. This is usually outside the scope of the product's implicit security policy.

Availability
Other
Alter Execution Logic
DoS: Crash, Exit, or Restart
DoS: Resource Consumption (CPU)
If the overflow/wraparound occurs in a loop index variable, this could cause the loop to terminate at the wrong time - too early, too late, or not at all (i.e., infinite loops). With too many iterations, some loops could consume too many resources such as memory, file handles, etc., possibly leading to a crash or other DoS.

Access Control
Bypass Protection Mechanism
If integer values are used in security-critical decisions, such as calculating quotas or allocation limits, integer overflows can be used to cause an incorrect security decision.

Automated Static Analysis
This weakness can often be detected using automated static analysis tools. Many modern tools use data flow analysis or constraint-based techniques to minimize the number of false positives.
High

Black Box
Sometimes, evidence of this weakness can be detected using dynamic tools and techniques that interact with the product using large test suites with many diverse inputs, such as fuzz testing (fuzzing), robustness testing, and fault injection. The product's operation may slow down, but it should not become unstable, crash, or generate incorrect results.
Moderate
Without visibility into the code, black box methods may not be able to sufficiently distinguish this weakness from others, requiring follow-up manual methods to diagnose the underlying problem.

Manual Analysis

This weakness can be detected using tools and techniques that require manual (human) analysis, such as penetration testing, threat modeling, and interactive tools that allow the tester to record and modify an active session.
Specifically, manual static analysis is useful for evaluating the correctness of allocation calculations. This can be useful for detecting overflow conditions (CWE-190) or similar weaknesses that might have serious security impacts on the program.

High
These may be more effective than strictly automated techniques. This is especially the case with weaknesses that are related to design and business rules.

Automated Static Analysis - Binary or Bytecode

According to SOAR [REF-1479], the following detection techniques may be useful:

Highly cost effective:

Bytecode Weakness Analysis - including disassembler + source code weakness analysis
Binary Weakness Analysis - including disassembler + source code weakness analysis

High

Dynamic Analysis with Manual Results Interpretation

According to SOAR [REF-1479], the following detection techniques may be useful:

Cost effective for partial coverage:

Fuzz Tester
Framework-based Fuzzer

SOAR Partial

Manual Static Analysis - Source Code

According to SOAR [REF-1479], the following detection techniques may be useful:

Cost effective for partial coverage:

Manual Source Code Review (not inspections)

SOAR Partial

Automated Static Analysis - Source Code

According to SOAR [REF-1479], the following detection techniques may be useful:

Highly cost effective:

Source code Weakness Analyzer
Context-configured Source Code Weakness Analyzer

High

Architecture or Design Review

According to SOAR [REF-1479], the following detection techniques may be useful:

Highly cost effective:

Formal Methods / Correct-By-Construction

Cost effective for partial coverage:

Inspection (IEEE 1028 standard) (can apply to requirements, design, source code, etc.)

High

Requirements
Ensure that all protocols are strictly defined, such that all out-of-bounds behavior can be identified simply, and require strict conformance to the protocol.

Requirements
Language Selection

Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
If possible, choose a language or compiler that performs automatic bounds checking.

Architecture and Design
Libraries or Frameworks

Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid [REF-1482].
Use libraries or frameworks that make it easier to handle numbers without unexpected consequences.
Examples include safe integer handling packages such as SafeInt (C++) or IntegerLib (C or C++). [REF-106]

Implementation
Input Validation

Perform input validation on any numeric input by ensuring that it is within the expected range. Enforce that the input meets both the minimum and maximum requirements for the expected range.
Use unsigned integers where possible. This makes it easier to perform validation for integer overflows. When signed integers are required, ensure that the range check includes minimum values as well as maximum values.

Implementation

Understand the programming language's underlying representation and how it interacts with numeric calculation (CWE-681). Pay close attention to byte size discrepancies, precision, signed/unsigned distinctions, truncation, conversion and casting between types, "not-a-number" calculations, and how the language handles numbers that are too large or too small for its underlying representation. [REF-7]
Also be careful to account for 32-bit, 64-bit, and other potential differences that may affect the numeric representation.

Architecture and Design
For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.

Implementation
Compilation or Build Hardening
Examine compiler warnings closely and eliminate problems with potential security implications, such as signed / unsigned mismatch in memory operations, or use of uninitialized variables. Even if the weakness is rarely exploitable, a single failure may lead to the compromise of the entire system.

The following image processing code allocates a table for images.

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).

The following code excerpt from OpenSSH 3.3 demonstrates a classic case of integer overflow:

nresp = packet_get_int();if (nresp > 0) {response = xmalloc(nresp*sizeof(char*));for (i = 0; i < nresp; i++) response[i] = packet_get_string(NULL);}

If nresp has the value 1073741824 and sizeof(char*) has its typical value of 4, then the result of the operation nresp*sizeof(char*) overflows, and the argument to xmalloc() will be 0. Most malloc() implementations will happily allocate a 0-byte buffer, causing the subsequent loop iterations to overflow the heap buffer response.

Integer overflows can be complicated and difficult to detect. The following example is an attempt to show how an integer overflow may lead to undefined looping behavior:

short int bytesRec = 0;char buf[SOMEBIGNUM];
while(bytesRec < MAXGET) {bytesRec += getFromInput(buf+bytesRec);}

In the above case, it is entirely possible that bytesRec may overflow, continuously creating a lower number than MAXGET and also overwriting the first MAXGET-1 bytes of buf.

In this example the method determineFirstQuarterRevenue is used to determine the first quarter revenue for an accounting/business application. The method retrieves the monthly sales totals for the first three months of the year, calculates the first quarter sales totals from the monthly sales totals, calculates the first quarter revenue based on the first quarter sales, and finally saves the first quarter revenue results to the database.

#define JAN 1#define FEB 2#define MAR 3
short getMonthlySales(int month) {...}
float calculateRevenueForQuarter(short quarterSold) {...}
int determineFirstQuarterRevenue() {

// Variable for sales revenue for the quarter
float quarterRevenue = 0.0f;
short JanSold = getMonthlySales(JAN); /* Get sales in January */short FebSold = getMonthlySales(FEB); /* Get sales in February */short MarSold = getMonthlySales(MAR); /* Get sales in March */

// Calculate quarterly total
short quarterSold = JanSold + FebSold + MarSold;

// Calculate the total revenue for the quarter
quarterRevenue = calculateRevenueForQuarter(quarterSold);
saveFirstQuarterRevenue(quarterRevenue);
return 0;
}

However, in this example the primitive type short int is used for both the monthly and the quarterly sales variables. In C the short int primitive type has a maximum value of 32768. This creates a potential integer overflow if the value for the three monthly sales adds up to more than the maximum value for the short int primitive type. An integer overflow can lead to data corruption, unexpected behavior, infinite loops and system crashes. To correct the situation the appropriate primitive type should be used, as in the example below, and/or provide some validation mechanism to ensure that the maximum value for the primitive type is not exceeded.

...float calculateRevenueForQuarter(long quarterSold) {...}
int determineFirstQuarterRevenue() {
...
// Calculate quarterly total
long quarterSold = JanSold + FebSold + MarSold;

// Calculate the total revenue for the quarter
quarterRevenue = calculateRevenueForQuarter(quarterSold);
...
}

Note that an integer overflow could also occur if the quarterSold variable has a primitive type long but the method calculateRevenueForQuarter has a parameter of type short.

CVE-2025-46687
Chain: Javascript engine code does not perform a length check (CWE-1284) leading to integer overflow (CWE-190) causing allocation of smaller buffer than expected (CWE-131) resulting in a heap-based buffer overflow (CWE-122)
https://www.cve.org/CVERecord?id=CVE-2025-46687

CVE-2025-27363
Font rendering library does not properly
handle assigning a signed short value to an unsigned
long (CWE-195), leading to an integer wraparound
(CWE-190), causing too small of a buffer (CWE-131),
leading to an out-of-bounds write
(CWE-787).
https://www.cve.org/CVERecord?id=CVE-2025-27363

CVE-2021-43537
Chain: in a web browser, an unsigned 64-bit integer is forcibly cast to a 32-bit integer (CWE-681) and potentially leading to an integer overflow (CWE-190). If an integer overflow occurs, this can cause heap memory corruption (CWE-122)
https://www.cve.org/CVERecord?id=CVE-2021-43537

CVE-2019-19911
Chain: Python library does not limit the resources used to process images that specify a very large number of bands (CWE-1284), leading to excessive memory consumption (CWE-789) or an integer overflow (CWE-190).
https://www.cve.org/CVERecord?id=CVE-2019-19911

CVE-2022-0545
Chain: 3D renderer has an integer overflow (CWE-190) leading to write-what-where condition (CWE-123) using a crafted image.
https://www.cve.org/CVERecord?id=CVE-2022-0545

CVE-2021-30860
Chain: improper input validation (CWE-20) leads to integer overflow (CWE-190) in mobile OS, as exploited in the wild per CISA KEV.
https://www.cve.org/CVERecord?id=CVE-2021-30860

CVE-2021-30663
Chain: improper input validation (CWE-20) leads to integer overflow (CWE-190) in mobile OS, as exploited in the wild per CISA KEV.
https://www.cve.org/CVERecord?id=CVE-2021-30663

CVE-2018-10887
Chain: unexpected sign extension (CWE-194) leads to integer overflow (CWE-190), causing an out-of-bounds read (CWE-125)
https://www.cve.org/CVERecord?id=CVE-2018-10887

CVE-2019-1010006
Chain: compiler optimization (CWE-733) removes or modifies code used to detect integer overflow (CWE-190), allowing out-of-bounds write (CWE-787).
https://www.cve.org/CVERecord?id=CVE-2019-1010006

CVE-2010-1866
Chain: integer overflow (CWE-190) causes a negative signed value, which later bypasses a maximum-only check (CWE-839), leading to heap-based buffer overflow (CWE-122).
https://www.cve.org/CVERecord?id=CVE-2010-1866

CVE-2010-2753
Chain: integer overflow leads to use-after-free
https://www.cve.org/CVERecord?id=CVE-2010-2753

CVE-2005-1513
Chain: integer overflow in securely-coded mail program leads to buffer overflow. In 2005, this was regarded as unrealistic to exploit, but in 2020, it was rediscovered to be easier to exploit due to evolutions of the technology.
https://www.cve.org/CVERecord?id=CVE-2005-1513

CVE-2002-0391
Integer overflow via a large number of arguments.
https://www.cve.org/CVERecord?id=CVE-2002-0391

CVE-2002-0639
Integer overflow in OpenSSH as listed in the demonstrative examples.
https://www.cve.org/CVERecord?id=CVE-2002-0639

CVE-2005-1141
Image with large width and height leads to integer overflow.
https://www.cve.org/CVERecord?id=CVE-2005-1141

CVE-2005-0102
Length value of -1 leads to allocation of 0 bytes and resultant heap overflow.
https://www.cve.org/CVERecord?id=CVE-2005-0102

CVE-2004-2013
Length value of -1 leads to allocation of 0 bytes and resultant heap overflow.
https://www.cve.org/CVERecord?id=CVE-2004-2013

CVE-2017-1000121
chain: unchecked message size metadata allows integer overflow (CWE-190) leading to buffer overflow (CWE-119).
https://www.cve.org/CVERecord?id=CVE-2017-1000121

CVE-2013-1591
Chain: an integer overflow (CWE-190) in the image size calculation causes an infinite loop (CWE-835) which sequentially allocates buffers without limits (CWE-1325) until the stack is full.
https://www.cve.org/CVERecord?id=CVE-2013-1591

Number Processing
Memory Management
Counters

Integer overflow (wrap or wraparound)

Integer Overflow

Integer overflow

INT18-C
Evaluate integer expressions in a larger size before comparing or assigning to that size
CWE More Abstract

INT30-C
Ensure that unsigned integer operations do not wrap
CWE More Abstract

INT32-C
Ensure that operations on signed integers do not result in overflow
Imprecise

INT35-C
Evaluate integer expressions in a larger size before comparing or assigning to that size

MEM07-C
Ensure that the arguments to calloc(), when multiplied, do not wrap
CWE More Abstract

MEM35-C
Allocate sufficient memory for an object

3
Integer Overflows

SFP1
Glitch in computation

Part 3-3
Req SR 3.5

Part 3-3
Req SR 7.2

Part 4-1
Req SR-2

Part 4-1
Req SI-2

Part 4-1
Req SVV-1

Part 4-1
Req SVV-3

Part 4-2
Req CR 3.5

Part 4-2
Req CR 7.2

Allowed
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.
Be careful of terminology problems with "overflow," "underflow," and "wraparound" - see Terminology Notes. 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.

Integer overflows can be primary to buffer overflows when they cause less memory to be allocated than expected.

"Integer overflow" is
sometimes used to cover several types of errors, including
signedness errors, or buffer overflows that involve
manipulation of integer data types instead of
characters. Part of the confusion results from the fact
that 0xffffffff is -1 in a signed context. Other confusion
also arises because of the role that integer overflows
have in chains.

A "wraparound" is a well-defined, standard
behavior that follows specific rules for how to handle
situations when the intended numeric value is too large or
too small to be represented, as specified in standards
such as C11.

"Overflow" is sometimes conflated with
"wraparound" but typically indicates a non-standard or
undefined behavior.

The "overflow" term is sometimes used to indicate
cases where either the maximum or the minimum is exceeded,
but others might only use "overflow" to indicate exceeding
the maximum while using "underflow" for exceeding the
minimum.

Some people use "overflow" to mean any value
outside the representable range - whether greater than the
maximum, or less than the minimum - but CWE uses
"underflow" for cases in which the intended result is less
than the minimum.

See [REF-1440] for additional explanation of the
ambiguity of terminology.

While there may be circumstances in
which the logic intentionally relies on wrapping - such as
with modular arithmetic in timers or counters - it can
have security consequences if the wrap is unexpected.
This is especially the case if the integer overflow can be
triggered using user-supplied inputs.

PLOVER
2006-07-19
Draft 3
2006-07-19

CWE Content Team
MITRE
2008-09-08
updated Common_Consequences, Relationships, Relationship_Notes, Taxonomy_Mappings, Terminology_Notes

CWE Content Team
MITRE
2008-10-14
updated Common_Consequences, Description, Potential_Mitigations, Terminology_Notes

CWE Content Team
MITRE
2008-11-24
updated Relationships, Taxonomy_Mappings

CWE Content Team
MITRE
2009-01-12
updated Description, Name

CWE Content Team
MITRE
2009-05-27
updated Demonstrative_Examples

CWE Content Team
MITRE
2009-10-29
updated Relationships

CWE Content Team
MITRE
2010-02-16
updated Applicable_Platforms, Detection_Factors, Functional_Areas, Observed_Examples, Potential_Mitigations, References, Related_Attack_Patterns, Relationships, Taxonomy_Mappings, Terminology_Notes

CWE Content Team
MITRE
2010-04-05
updated Demonstrative_Examples, Detection_Factors, Potential_Mitigations, References, Related_Attack_Patterns

CWE Content Team
MITRE
2010-06-21
updated Common_Consequences, Potential_Mitigations, References

CWE Content Team
MITRE
2010-09-27
updated Observed_Examples, Potential_Mitigations

CWE Content Team
MITRE
2011-06-01
updated Common_Consequences

CWE Content Team
MITRE
2011-06-27
updated Relationships

CWE Content Team
MITRE
2011-09-13
updated Potential_Mitigations, References, Relationships, Taxonomy_Mappings

CWE Content Team
MITRE
2012-05-11
updated Common_Consequences, Demonstrative_Examples, References, Relationships

CWE Content Team
MITRE
2012-10-30
updated Potential_Mitigations

CWE Content Team
MITRE
2013-07-17
updated References

CWE Content Team
MITRE
2014-07-30
updated Detection_Factors, Relationships, Taxonomy_Mappings

CWE Content Team
MITRE
2015-12-07
updated Relationships

CWE Content Team
MITRE
2017-01-19
updated Relationships

CWE Content Team
MITRE
2017-11-08
updated Functional_Areas, Observed_Examples, References, Taxonomy_Mappings

CWE Content Team
MITRE
2018-03-27
updated References

CWE Content Team
MITRE
2019-01-03
updated Relationships

CWE Content Team
MITRE
2019-09-19
updated Relationships

CWE Content Team
MITRE
2020-02-24
updated Relationships

CWE Content Team
MITRE
2020-06-25
updated Observed_Examples

CWE Content Team
MITRE
2020-08-20
updated Relationships

CWE Content Team
MITRE
2020-12-10
updated Observed_Examples

CWE Content Team
MITRE
2021-03-15
updated Potential_Mitigations

CWE Content Team
MITRE
2021-07-20
updated Relationships

CWE Content Team
MITRE
2022-06-28
updated Observed_Examples, Relationships

CWE Content Team
MITRE
2022-10-13
updated Observed_Examples

CWE Content Team
MITRE
2023-01-31
updated Description, Detection_Factors

CWE Content Team
MITRE
2023-04-27
updated Relationships, Taxonomy_Mappings

CWE Content Team
MITRE
2023-06-29
updated Mapping_Notes, Relationships

CWE Content Team
MITRE
2023-10-26
updated Observed_Examples

CWE Content Team
MITRE
2024-02-29
4.14
2024-02-29
updated Observed_Examples

CWE Content Team
MITRE
2024-07-16
4.15
2024-07-16
updated Alternate_Terms, Common_Consequences, Description, Diagram, Mapping_Notes, Modes_of_Introduction, Other_Notes, References, Relationship_Notes, Terminology_Notes

CWE Content Team
MITRE
2024-11-19
4.16
2024-11-19
updated Relationships

CWE Content Team
MITRE
2025-04-03
4.17
2025-04-03
updated Applicable_Platforms, Observed_Examples

CWE Content Team
MITRE
2025-09-09
4.18
2025-09-09
updated Detection_Factors, Observed_Examples, Potential_Mitigations, References

CWE Content Team
MITRE
2025-12-11
4.19
2025-12-11
updated Applicable_Platforms, Observed_Examples, Weakness_Ordinalities

"Mapping CWE to 62443" Sub-Working Group
CWE-CAPEC ICS/OT SIG
2023-04-25
Suggested mappings to ISA/IEC 62443.

Abhi Balakrishnan
2024-02-29
4.15
2024-07-16
Provided diagram to improve CWE usability

Zheng Zhang
Purdue University
2025-06-16
4.18
2025-09-09
reported CVE-2022-21668 as an incorrect observed example for this entry, when CVE-2019-19911 was intended

Integer Overflow (Wrap or Wraparound)