CWE-244: Improper Clearing of Heap Memory Before Release ('Heap Inspection')
Weakness ID: 244
Using realloc() to resize buffers that store sensitive information can leave the sensitive information exposed to attack, because it is not removed from memory.
When sensitive data such as a password or an encryption key is not removed from memory, it could be exposed to an attacker using a "heap inspection" attack that reads the sensitive data using memory dumps or other methods. The realloc() function is commonly used to increase the size of a block of allocated memory. This operation often requires copying the contents of the old memory block into a new and larger block. This operation leaves the contents of the original block intact but inaccessible to the program, preventing the program from being able to scrub sensitive data from memory. If an attacker can later examine the contents of a memory dump, the sensitive data could be exposed.
Time of Introduction
Technical Impact: Read memory; Other
Be careful using vfork() and fork() in security sensitive code. The
process state will not be cleaned up and will contain traces of data
from past use.
The following code calls realloc() on a buffer containing sensitive