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CWE-469

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CWE-469

Use of Pointer Subtraction to Determine Size

Base
Draft

Description

The product subtracts one pointer from another in order to determine size, but this calculation can be incorrect if the pointers do not exist in the same memory chunk.

Parent Weaknesses (ChildOf)

Common Consequences

Scope

Access Control
Integrity
Confidentiality
Availability

Impact

Modify Memory, Read Memory, Execute Unauthorized Code or Commands, Gain Privileges or Assume Identity

Potential Mitigations

Implementation

Save an index variable. This is the recommended solution. Rather than subtract pointers from one another, use an index variable of the same size as the pointers in question. Use this variable to "walk" from one pointer to the other and calculate the difference. Always validate this number.

Applicable Platforms

C
C++

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