CWE-176 詳細

CWE-176

Improper Handling of Unicode Encoding
2006-07-19
00h00 +00:00
Draft
2026-10-28
00h00 +00:00
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名前: Improper Handling of Unicode Encoding

The product does not properly handle when an input contains Unicode encoding.

一般情報

導入モード

Implementation

適用可能なプラットフォーム

言語

クラス: Not Language-Specific (Undetermined)
名前: Python (Undetermined)

テクノロジー

クラス: Not Technology-Specific (Undetermined)

一般的な結果

スコープ 影響 可能性
IntegrityUnexpected State

観察された例

参考文献 説明

CVE-2000-0884

Server allows remote attackers to read documents outside of the web root, and possibly execute arbitrary commands, via malformed URLs that contain Unicode encoded characters.

CVE-2001-0709

Server allows a remote attacker to obtain source code of ASP files via a URL encoded with Unicode.

CVE-2001-0669

Overlaps interaction error.

潜在的な緩和策

Phases : Architecture and Design
Avoid making decisions based on names of resources (e.g. files) if those resources can have alternate names.
Phases : Implementation
Phases : Implementation
Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked.

検出方法

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.)

脆弱性マッピングノート

理由 : 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.
コメント : 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.

関連する攻撃パターン

CAPEC ID 攻撃パターン名
CAPEC-71 Using Unicode Encoding to Bypass Validation Logic
An attacker may provide a Unicode string to a system component that is not Unicode aware and use that to circumvent the filter or cause the classifying mechanism to fail to properly understanding the request. That may allow the attacker to slip malicious data past the content filter and/or possibly cause the application to route the request incorrectly.

参考文献

REF-62

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

REF-1541

Secure Coding Guide for Python
OpenSSF.
https://best.openssf.org/Secure-Coding-Guide-for-Python/

登録情報

名前 組織 日付 リリース日 Version
PLOVER 2006-07-19 +00:00 2006-07-19 +00:00 Draft 3

変更履歴

名前 組織 日付 コメント
Eric Dalci Cigital 2008-07-01 +00:00 updated Potential_Mitigations, Time_of_Introduction
CWE Content Team MITRE 2008-09-08 +00:00 updated Relationships, Taxonomy_Mappings
CWE Content Team MITRE 2008-11-24 +00:00 updated Relationships, Taxonomy_Mappings
CWE Content Team MITRE 2009-03-10 +00:00 updated Demonstrative_Examples
CWE Content Team MITRE 2009-05-27 +00:00 updated Demonstrative_Examples
CWE Content Team MITRE 2009-07-27 +00:00 updated Potential_Mitigations
CWE Content Team MITRE 2010-12-13 +00:00 updated Name
CWE Content Team MITRE 2011-03-29 +00:00 updated Potential_Mitigations
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 2011-09-13 +00:00 updated Relationships, Taxonomy_Mappings
CWE Content Team MITRE 2012-05-11 +00:00 updated Observed_Examples, References, Relationships
CWE Content Team MITRE 2012-10-30 +00:00 updated Potential_Mitigations
CWE Content Team MITRE 2014-07-30 +00:00 updated Relationships
CWE Content Team MITRE 2017-11-08 +00:00 updated Applicable_Platforms, Taxonomy_Mappings
CWE Content Team MITRE 2020-02-24 +00:00 updated Potential_Mitigations, Relationships
CWE Content Team MITRE 2020-06-25 +00:00 updated Potential_Mitigations
CWE Content Team MITRE 2023-01-31 +00:00 updated Description
CWE Content Team MITRE 2023-04-27 +00:00 updated Relationships
CWE Content Team MITRE 2023-06-29 +00:00 updated Mapping_Notes
CWE Content Team MITRE 2024-02-29 +00:00 updated Demonstrative_Examples
CWE Content Team MITRE 2025-12-11 +00:00 updated Applicable_Platforms, Weakness_Ordinalities
CWE Content Team MITRE 2026-10-28 +00:00 updated Applicable_Platforms, Detection_Factors, References, Relationships, Taxonomy_Mappings