CWE-242 使用内在危险函数

Use of Inherently Dangerous Function

结构: Simple

Abstraction: Base

状态: Draft

被利用可能性: High

基本描述

The program calls a function that can never be guaranteed to work safely.

扩展描述

Certain functions behave in dangerous ways regardless of how they are used. Functions in this category were often implemented without taking security concerns into account. The gets() function is unsafe because it does not perform bounds checking on the size of its input. An attacker can easily send arbitrarily-sized input to gets() and overflow the destination buffer. Similarly, the >> operator is unsafe to use when reading into a statically-allocated character array because it does not perform bounds checking on the size of its input. An attacker can easily send arbitrarily-sized input to the >> operator and overflow the destination buffer.

相关缺陷

• cwe_Nature: ChildOf cwe_CWE_ID: 1177 cwe_View_ID: 1000 cwe_Ordinal: Primary

适用平台

Language: [{'cwe_Name': 'C', 'cwe_Prevalence': 'Undetermined'}, {'cwe_Name': 'C++', 'cwe_Prevalence': 'Undetermined'}]

常见的影响

可能的缓解方案

['Implementation', 'Requirements']

策略:

Ban the use of dangerous functions. Use their safe equivalent.

Testing

策略:

Use grep or static analysis tools to spot usage of dangerous functions.

示例代码

例

The code below calls gets() to read information into a buffer.

bad C

The gets() function in C is inherently unsafe.

例

The code below calls the gets() function to read in data from the command line.

bad C

However, the programmer uses the function gets() which is inherently unsafe because it blindly copies all input from STDIN to the buffer without checking size. This allows the user to provide a string that is larger than the buffer size, resulting in an overflow condition.

分类映射

引用

• REF-194 Herb Schildt's C++ Programming Cookbook

• REF-7 Writing Secure Code