이름: Signed to Unsigned Conversion Error

The product uses a signed primitive and performs a cast to an unsigned primitive, which can produce an unexpected value if the value of the signed primitive can not be represented using an unsigned primitive.

일반 정보

취약점 도입 방식

Implementation : It is dangerous to rely on implicit casts between signed and unsigned numbers because the result can take on an unexpected value and violate assumptions made by the program.

적용 가능한 플랫폼

언어

이름: C (Undetermined)
이름: C++ (Undetermined)

일반적인 결과

범위	영향	가능성
Integrity	Unexpected State, Modify Memory, Read Memory 참고: Conversion between signed and unsigned values can lead to a variety of errors, but from a security standpoint is most commonly associated with integer overflow and buffer overflow vulnerabilities. Often, functions will return negative values to indicate a failure. When the result of a function is to be used as a size parameter, using these negative return values can have unexpected results. For example, if negative size values are passed to the standard memory copy or allocation functions, they will be implicitly cast to a large unsigned value. This may lead to an exploitable buffer overflow or underflow condition.

관찰된 예시

참고 자료	설명
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).
CVE-2007-4268	Chain: integer signedness error (CWE-195) passes signed comparison, leading to heap overflow (CWE-122)

탐지 방법

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.)
효과성 : High

취약점 매핑 메모

근거 : This CWE entry is at the Variant level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities.
댓글 : 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.

참고 자료

REF-62

The Art of Software Security Assessment
Mark Dowd, John McDonald, Justin Schuh.

REF-18

The CLASP Application Security Process
Secure Software, Inc..
https://cwe.mitre.org/documents/sources/TheCLASPApplicationSecurityProcess.pdf

REF-1534

Automated Technical Debt Measure, Version 2
OMG.
https://www.omg.org/spec/ATDM2/1.0/PDF

제출

이름	조직	날짜	출시일	Version
CLASP		2006-07-19 +00:00	2006-07-19 +00:00	Draft 3

수정 사항

이름	조직	날짜	댓글
CWE Content Team	MITRE	2008-09-08 +00:00	updated Applicable_Platforms, Common_Consequences, Relationships, Other_Notes, Taxonomy_Mappings
CWE Content Team	MITRE	2009-05-27 +00:00	updated Demonstrative_Examples
CWE Content Team	MITRE	2009-10-29 +00:00	updated Common_Consequences, Description, Other_Notes, Relationships
CWE Content Team	MITRE	2010-02-16 +00:00	updated Demonstrative_Examples
CWE Content Team	MITRE	2010-04-05 +00:00	updated Demonstrative_Examples
CWE Content Team	MITRE	2011-03-29 +00:00	updated Relationships
CWE Content Team	MITRE	2011-06-01 +00:00	updated Common_Consequences
CWE Content Team	MITRE	2011-06-27 +00:00	updated Common_Consequences
CWE Content Team	MITRE	2012-05-11 +00:00	updated Demonstrative_Examples, References, Relationships
CWE Content Team	MITRE	2014-06-23 +00:00	updated Demonstrative_Examples, Description
CWE Content Team	MITRE	2014-07-30 +00:00	updated Relationships, Taxonomy_Mappings
CWE Content Team	MITRE	2017-01-19 +00:00	updated Relationships
CWE Content Team	MITRE	2017-11-08 +00:00	updated Observed_Examples, Taxonomy_Mappings
CWE Content Team	MITRE	2019-01-03 +00:00	updated Relationships
CWE Content Team	MITRE	2020-02-24 +00:00	updated Relationships
CWE Content Team	MITRE	2020-08-20 +00:00	updated Relationships
CWE Content Team	MITRE	2020-12-10 +00:00	updated Relationships
CWE Content Team	MITRE	2021-03-15 +00:00	updated Demonstrative_Examples, References
CWE Content Team	MITRE	2023-01-31 +00:00	updated Description
CWE Content Team	MITRE	2023-04-27 +00:00	updated Detection_Factors, Relationships
CWE Content Team	MITRE	2023-06-29 +00:00	updated Mapping_Notes
CWE Content Team	MITRE	2025-04-03 +00:00	updated Observed_Examples
CWE Content Team	MITRE	2025-12-11 +00:00	updated Weakness_Ordinalities
CWE Content Team	MITRE	2026-10-28 +00:00	updated Common_Consequences, Demonstrative_Examples, Description, Modes_of_Introduction, References

CWE-195 상세 정보

CWE-195