Chi tiết CWE-85

CWE-85

Doubled Character XSS Manipulations
2006-07-19
00h00 +00:00
Draft
2025-12-11
00h00 +00:00
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Quản lý thông báo

Tên: Doubled Character XSS Manipulations

The web application does not filter user-controlled input for executable script disguised using doubling of the involved characters.

Thông tin chung

Các cách xuất hiện

Implementation

Nền tảng áp dụng

Ngôn ngữ

Lớp: Not Language-Specific (Undetermined)

Công nghệ

Lớp: Web Based (Undetermined)
Tên: Web Server (Undetermined)

Hậu quả phổ biến

Phạm vi Tác động Khả năng xảy ra
Confidentiality
Integrity
Availability
Read Application Data, Execute Unauthorized Code or Commands

Ví dụ đã quan sát

Tài liệu tham khảo Mô tả

CVE-2002-2086

XSS using "

CVE-2000-0116

Encoded "javascript" in IMG tag.

CVE-2001-1157

Extra "<" in front of SCRIPT tag.

Các biện pháp giảm thiểu tiềm năng

Phases : Implementation
Resolve all filtered input to absolute or canonical representations before processing.
Phases : Implementation
Carefully check each input parameter against a rigorous positive specification (allowlist) defining the specific characters and format allowed. All input should be neutralized, not just parameters that the user is supposed to specify, but all data in the request, including tag attributes, hidden fields, cookies, headers, the URL itself, and so forth. A common mistake that leads to continuing XSS vulnerabilities is to validate only fields that are expected to be redisplayed by the site. We often encounter data from the request that is reflected by the application server or the application that the development team did not anticipate. Also, a field that is not currently reflected may be used by a future developer. Therefore, validating ALL parts of the HTTP request is recommended.
Phases : Implementation
Phases : Implementation
With Struts, write all data from form beans with the bean's filter attribute set to true.
Phases : Implementation
To help mitigate XSS attacks against the user's session cookie, set the session cookie to be HttpOnly. In browsers that support the HttpOnly feature (such as more recent versions of Internet Explorer and Firefox), this attribute can prevent the user's session cookie from being accessible to malicious client-side scripts that use document.cookie. This is not a complete solution, since HttpOnly is not supported by all browsers. More importantly, XmlHttpRequest and other powerful browser technologies provide read access to HTTP headers, including the Set-Cookie header in which the HttpOnly flag is set.

Ghi chú ánh xạ lỗ hổng

Lý do : 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.
Bình luận : 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.

Mẫu tấn công liên quan

ID CAPEC Tên mẫu tấn công
CAPEC-245 XSS Using Doubled Characters
The adversary bypasses input validation by using doubled characters in order to perform a cross-site scripting attack. Some filters fail to recognize dangerous sequences if they are preceded by repeated characters. For example, by doubling the < before a script command, (<