CWE-80: Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)
CWE版本: 4.18
更新日期: 2025-09-09
弱点描述
The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes special characters such as "<", ">", and "&" that could be interpreted as web-scripting elements when they are sent to a downstream component that processes web pages.
常见后果
影响范围: Confidentiality Integrity Availability
技术影响: Read Application Data Execute Unauthorized Code or Commands
说明: An attacker could insert special characters that are processed client-side in the context of the user's session.
潜在缓解措施
阶段: Implementation
描述: 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 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.
阶段: Implementation
策略: Output Encoding
阶段: Implementation
描述: With Struts, write all data from form beans with the bean's filter attribute set to true.
阶段: Implementation
策略: Attack Surface Reduction
描述: 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.
有效性: Defense in Depth
检测方法
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
观察示例
参考: CVE-2002-0938
XSS in parameter in a link.
参考: CVE-2002-1495
XSS in web-based email product via attachment filenames.
参考: CVE-2003-1136
HTML injection in posted message.
参考: CVE-2004-2171
XSS not quoted in error page.
引入模式
| 阶段 | 说明 |
|---|---|
| Implementation | - |
适用平台
编程语言
分类映射
| 分类名称 | 条目ID | 条目名称 | 映射适配度 |
|---|---|---|---|
| PLOVER | - | Basic XSS | - |
| Software Fault Patterns | SFP24 | Tainted input to command | - |
关键信息
CWE ID: CWE-80
抽象级别: Variant
结构: Simple
状态: Incomplete
利用可能性: High