名稱: Unsigned to Signed Conversion Error
The product uses an unsigned primitive and performs a cast to a signed primitive, which can produce an unexpected value if the value of the unsigned primitive can not be represented using a signed primitive.
一般資訊
引入方式
Implementation適用平台
程式語言
名稱： C (Undetermined)名稱： C++ (Undetermined)
常見後果
| 範圍 | 影響 | 可能性 |
|---|---|---|
| Availability | DoS: Crash, Exit, or Restart 注意：Incorrect sign conversions generally lead to undefined behavior, and therefore crashes. | |
| Integrity | Modify Memory 注意：If a poor cast leads to a buffer overflow or similar condition, data integrity may be affected. This can be a precursor to dangerous buffer underwrite conditions that allow attackers to move down the stack where they otherwise might not have access in a normal buffer overflow condition. Buffer underwrites occur frequently when large unsigned values are cast to signed values, and then used as indexes into a buffer or for pointer arithmetic. | |
| Integrity Confidentiality Availability Access Control | Execute Unauthorized Code or Commands, Bypass Protection Mechanism 注意：Improper signed-to-unsigned conversions without proper checking 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. |
潛在緩解措施
Phases : RequirementsChoose a language which is not subject to these casting flaws.
Phases : Architecture and Design
Design object accessor functions to implicitly check values for valid sizes. Ensure that all functions which will be used as a size are checked previous to use as a size. If the language permits, throw exceptions rather than using in-band errors.
Phases : Implementation
Error check the return values of all functions. Be aware of implicit casts made, and use unsigned variables for sizes if at all possible.
偵測方法
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.)有效性 : High
漏洞對應備注
理由說明 : 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.備註 : 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.
相關攻擊模式
| CAPEC ID | 攻擊模式名稱 |
|---|---|
| CAPEC-92 | Forced Integer Overflow
This attack forces an integer variable to go out of range. The integer variable is often used as an offset such as size of memory allocation or similarly. The attacker would typically control the value of such variable and try to get it out of range. For instance the integer in question is incremented past the maximum possible value, it may wrap to become a very small, or negative number, therefore providing a very incorrect value which can lead to unexpected behavior. At worst the attacker can execute arbitrary code. |
參考資料
REF-62
The Art of Software Security AssessmentMark Dowd, John McDonald, Justin Schuh.
REF-18
The CLASP Application Security ProcessSecure Software, Inc..
https://cwe.mitre.org/documents/sources/TheCLASPApplicationSecurityProcess.pdf
REF-1534
Automated Technical Debt Measure, Version 2OMG.
https://www.omg.org/spec/ATDM2/1.0/PDF
提交
| 名稱 | 機構 | 日期 | 發布日期 | Version |
|---|---|---|---|---|
| CLASP | Draft 3 |
修改記錄
| 名稱 | 機構 | 日期 | 備註 |
|---|---|---|---|
| CWE Content Team | MITRE | updated Applicable_Platforms, Common_Consequences, Relationships, Other_Notes, Taxonomy_Mappings | |
| CWE Content Team | MITRE | updated Demonstrative_Examples | |
| CWE Content Team | MITRE | updated Common_Consequences | |
| CWE Content Team | MITRE | updated Other_Notes | |
| CWE Content Team | MITRE | updated Common_Consequences | |
| CWE Content Team | MITRE | updated References, Relationships | |
| CWE Content Team | MITRE | updated Potential_Mitigations | |
| CWE Content Team | MITRE | updated Demonstrative_Examples, Description, Other_Notes | |
| CWE Content Team | MITRE | updated Relationships, Taxonomy_Mappings | |
| CWE Content Team | MITRE | updated Relationships | |
| CWE Content Team | MITRE | updated Relationships | |
| CWE Content Team | MITRE | updated Relationships | |
| CWE Content Team | MITRE | updated References | |
| CWE Content Team | MITRE | updated Description | |
| CWE Content Team | MITRE | updated Relationships | |
| CWE Content Team | MITRE | updated Mapping_Notes | |
| CWE Content Team | MITRE | updated Detection_Factors, Weakness_Ordinalities | |
| CWE Content Team | MITRE | updated Common_Consequences, Description, References, Relationships |
