CWE-838
Inappropriate Encoding for Output Context
2011-03-30
00h00 +00:00
00h00 +00:00
指定 CWE 通知
掌握特定 CWE 的任何變更。
名稱: Inappropriate Encoding for Output Context
The product uses or specifies an encoding when generating output to a downstream component, but the specified encoding is not the same as the encoding that is expected by the downstream component.
一般資訊
引入方式
Implementation適用平台
程式語言
類別： Not Language-Specific (Undetermined)常見後果
| 範圍 | 影響 | 可能性 |
|---|---|---|
| Integrity Confidentiality Availability | Modify Application Data, Execute Unauthorized Code or Commands 注意：An attacker could modify the structure of the message or data being sent to the downstream component. When the wrong encoding is used - even if closely related - the downstream component could decode the data incorrectly and misinterpret the output. This can have security consequences when the provided boundaries between control and data are inadvertently broken, because the resulting data could introduce control characters or special elements that were not sent by the product. The resulting data could then be used to bypass protection mechanisms such as input validation, and enable injection attacks. |
觀察到的案例
| 參考資料 | 描述 |
|---|---|
CVE-2009-2814 | Server does not properly handle requests that do not contain UTF-8 data; browser assumes UTF-8, allowing XSS. |
潛在緩解措施
Phases : ImplementationUse context-aware encoding. That is, understand which encoding is being used by the downstream component, and ensure that this encoding is used. If an encoding can be specified, do so, instead of assuming that the default encoding is the same as the default being assumed by the downstream component.
Phases : Architecture and Design
Where possible, use communications protocols or data formats that provide strict boundaries between control and data. If this is not feasible, ensure that the protocols or formats allow the communicating components to explicitly state which encoding/decoding method is being used. Some template frameworks provide built-in support.
Phases : Architecture and Design
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 Base 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-468 | Generic Cross-Browser Cross-Domain Theft
An attacker makes use of Cascading Style Sheets (CSS) injection to steal data cross domain from the victim's browser. The attack works by abusing the standards relating to loading of CSS: 1. Send cookies on any load of CSS (including cross-domain) 2. When parsing returned CSS ignore all data that does not make sense before a valid CSS descriptor is found by the CSS parser. |
參考資料
REF-786
Injection-safe templating languagesJim Manico.
https://manicode.blogspot.com/2010/06/injection-safe-templating-languages_30.html
REF-787
Can we please stop saying that XSS is boring and easy to fix!Dinis Cruz.
http://diniscruz.blogspot.com/2010/09/can-we-please-stop-saying-that-xss-is.html
REF-788
Canoe: XSS prevention via context-aware output encodingIvan Ristic.
https://blog.ivanristic.com/2010/09/introducing-canoe-context-aware-output-encoding-for-xss-prevention.html
REF-789
What is the Future of Automated XSS Defense Tools?Jim Manico.
http://software-security.sans.org/downloads/appsec-2011-files/manico-appsec-future-tools.pdf
REF-709
XSS AttacksJeremiah Grossman, Robert "RSnake" Hansen, Petko "pdp" D. Petkov, Anton Rager, Seth Fogie.
REF-725
DOM based XSS Prevention Cheat SheetOWASP.
http://www.owasp.org/index.php/DOM_based_XSS_Prevention_Cheat_Sheet
REF-45
OWASP Enterprise Security API (ESAPI) ProjectOWASP.
https://owasp.org/www-project-enterprise-security-api/
提交
| 名稱 | 機構 | 日期 | 發布日期 | Version |
|---|---|---|---|---|
| CWE Content Team | MITRE | 1.12 |
修改記錄
| 名稱 | 機構 | 日期 | 備註 |
|---|---|---|---|
| CWE Content Team | MITRE | updated Common_Consequences, Relationships, Taxonomy_Mappings | |
| CWE Content Team | MITRE | updated Demonstrative_Examples, Related_Attack_Patterns, Relationships | |
| CWE Content Team | MITRE | updated Potential_Mitigations, References, Relationships, Taxonomy_Mappings | |
| CWE Content Team | MITRE | updated References, Taxonomy_Mappings | |
| 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 Description | |
| CWE Content Team | MITRE | updated Detection_Factors, References, Relationships | |
| CWE Content Team | MITRE | updated Mapping_Notes | |
| CWE Content Team | MITRE | updated References | |
| CWE Content Team | MITRE | updated Time_of_Introduction, Weakness_Ordinalities | |
| CWE Content Team | MITRE | updated Common_Consequences, Description |
