CWE-547 使用硬编码、安全相关的常数

Use of Hard-coded, Security-relevant Constants

结构: Simple

Abstraction: Variant

状态: Draft

被利用可能性: unkown

基本描述

The program uses hard-coded constants instead of symbolic names for security-critical values, which increases the likelihood of mistakes during code maintenance or security policy change.

扩展描述

If the developer does not find all occurrences of the hard-coded constants, an incorrect policy decision may be made if one of the constants is not changed. Making changes to these values will require code changes that may be difficult or impossible once the system is released to the field. In addition, these hard-coded values may become available to attackers if the code is ever disclosed.

相关缺陷

  • cwe_Nature: ChildOf cwe_CWE_ID: 1078 cwe_View_ID: 1000 cwe_Ordinal: Primary

  • cwe_Nature: ChildOf cwe_CWE_ID: 1078 cwe_View_ID: 699 cwe_Ordinal: Primary

常见的影响

范围 影响 注释
Other ['Varies by Context', 'Quality Degradation'] The existence of hardcoded constants could cause unexpected behavior and the introduction of weaknesses during code maintenance or when making changes to the code if all occurrences are not modified. The use of hardcoded constants is an indication of poor quality.

可能的缓解方案

Implementation

策略:

Avoid using hard-coded constants. Configuration files offer a more flexible solution.

示例代码

例

The usage of symbolic names instead of hard-coded constants is preferred.

The following is an example of using a hard-coded constant instead of a symbolic name.

bad C

char buffer[1024];
...
fgets(buffer, 1024, stdin);

If the buffer value needs to be changed, then it has to be altered in more than one place. If the developer forgets or does not find all occurences, in this example it could lead to a buffer overflow.

bad C

enum { MAX_BUFFER_SIZE = 1024 };
...
char buffer[MAX_BUFFER_SIZE];
...
fgets(buffer, MAX_BUFFER_SIZE, stdin);

In this example the developer will only need to change one value and all references to the buffer size are updated, as a symbolic name is used instead of a hard-coded constant.

分类映射

映射的分类名 ImNode ID Fit Mapped Node Name
CERT C Secure Coding DCL06-C Use meaningful symbolic constants to represent literal values in program logic