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In this example, sensitive information in stored in the buffer secret is copied to the dynamically allocated buffer, new_buffsecret, which is then processed and eventually marked for deallocation with free(). However, the contents of new_buffsecret may remain in heap memory after being marked for deallocation. Furthermore, if this memory is recycled by the heap manager, the information stored in new_buffsecret may be exposed to another, unintended section of the program, or another program entirely.

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char *new_buffsecret;
size_t size = malloc(strlen(secret);
if (size == SIZE_MAX || size == 0) {
  /* Handle Error */
}

new_secret = malloc(size+1); /* allocate space + NULL Terminator */
if (!new_buffsecret) {
  /* Handle Error */
}
strcpy(new_buffsecret, secret);

/* Process new_buffsecret... */

free(new_buffsecret);
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Compliant Solution 1

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Code Block
bgColor #ccccff
... char *new_secret; size_t size = strlen(secret); if (size == SIZE_MAX || size == 0) { /* Handle Error */ } new_secret = malloc(size+1); /* allocate space + NULL Terminator */ if (!new_secret) { /* Handle Error */ } strcpy(new_secret, secret); /* Process new_secret... */ memset(new_secret,'\0',size); /* sanitize memory */ free(new_secret); ...

Non-Compliant Code Example 2

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