In addition to stack-based buffer overflow attacks (i.e., smashing the stack), heap overflows can also be...

  

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In addition to stack-based buffer overflow attacks (i.e., smashing the stack), heap overflows can also be exploited. Consider the following C code, which illustrates a heap overflow. int main() { int diff, size = 8; char *buf1, *buf2; buf1 (char *)malloc(size); } buf2 (char *)malloc(size); diff=buf2 - buf1; memset (buf2, '2', size); printf("BEFORE: buf2 = %s", buf2); memset (buf1, '1', diff + 3); printf("AFTER: buf2 = %s", buf2); return 0; (1) Compile and execute this program. What is printed? (2) Explain the results. (3) Explain how a heap overflow might be exploited by Trudy. In addition to stack-based buffer overflow attacks (i.e., smashing the stack), heap overflows can also be exploited. Consider the following C code, which illustrates a heap overflow. int main() { int diff, size = 8; char *buf1, *buf2; buf1 (char *)malloc(size); } buf2 (char *)malloc(size); diff=buf2 - buf1; memset (buf2, '2', size); printf("BEFORE: buf2 = %s", buf2); memset (buf1, '1', diff + 3); printf("AFTER: buf2 = %s", buf2); return 0; (1) Compile and execute this program. What is printed? (2) Explain the results. (3) Explain how a heap overflow might be exploited by Trudy.