CWE-488 对错误会话暴露数据元素

Exposure of Data Element to Wrong Session

结构: Simple

Abstraction: Variant

状态: Draft

被利用可能性: unkown

基本描述

The product does not sufficiently enforce boundaries between the states of different sessions, causing data to be provided to, or used by, the wrong session.

扩展描述

Data can "bleed" from one session to another through member variables of singleton objects, such as Servlets, and objects from a shared pool.

In the case of Servlets, developers sometimes do not understand that, unless a Servlet implements the SingleThreadModel interface, the Servlet is a singleton; there is only one instance of the Servlet, and that single instance is used and re-used to handle multiple requests that are processed simultaneously by different threads. A common result is that developers use Servlet member fields in such a way that one user may inadvertently see another user's data. In other words, storing user data in Servlet member fields introduces a data access race condition.

相关缺陷

  • cwe_Nature: ChildOf cwe_CWE_ID: 664 cwe_View_ID: 1000 cwe_Ordinal: Primary

  • cwe_Nature: ChildOf cwe_CWE_ID: 269 cwe_View_ID: 699 cwe_Ordinal: Primary

适用平台

Language: {'cwe_Class': 'Language-Independent', 'cwe_Prevalence': 'Undetermined'}

常见的影响

范围 影响 注释
Confidentiality Read Application Data

可能的缓解方案

Architecture and Design

策略:

Protect the application's sessions from information leakage. Make sure that a session's data is not used or visible by other sessions.

Testing

策略:

Use a static analysis tool to scan the code for information leakage vulnerabilities (e.g. Singleton Member Field).

Architecture and Design

策略:

In a multithreading environment, storing user data in Servlet member fields introduces a data access race condition. Do not use member fields to store information in the Servlet.

示例代码

例

The following Servlet stores the value of a request parameter in a member field and then later echoes the parameter value to the response output stream.

bad Java

public class GuestBook extends HttpServlet {
String name;

protected void doPost (HttpServletRequest req, HttpServletResponse res) {
name = req.getParameter("name");
...
out.println(name + ", thanks for visiting!");
}
}

While this code will work perfectly in a single-user environment, if two users access the Servlet at approximately the same time, it is possible for the two request handler threads to interleave in the following way: Thread 1: assign "Dick" to name Thread 2: assign "Jane" to name Thread 1: print "Jane, thanks for visiting!" Thread 2: print "Jane, thanks for visiting!" Thereby showing the first user the second user's name.

分类映射

映射的分类名 ImNode ID Fit Mapped Node Name
7 Pernicious Kingdoms Data Leaking Between Users

相关攻击模式

  • CAPEC-59
  • CAPEC-60