Tag: security

Questions Related to security

What vulnerability is present in following code: unsigned char j,k; j=getchar(); k=getchar(); unsigned char result = j + k;
technology security

  1. Heap Overflow

  2. Integer overflow

  3. Buffer overflow

  4. No Vulnerability

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Correct Option: B

Which statement creates a buffer over flow? #include #include #include int main (int argc, char *argv[]) { int i=0,j=1; char ipstring[80]; for (;i<=3;i++){ cout<
technology security

  1. j=getchar();

  2. gets(ipstring);

  3. Both

  4. None

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Correct Option: B

In this code, x is freed twice. What is the risk of this code? x = malloc(200); /* do something with x / free(x); / do something else */ free(x);
technology security

  1. This is a double free vulnerability and must be fixed

  2. The second call to free() will return an error

  3. There might be compiler warnings, but the program will run fine

  4. This is not a security issue

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Correct Option: A

Is there a vulnerability in this code? If yes, which line(s) int main (int argc, char argv[]){ char chararray[3]; int intarray[3]; int i; strncpy(chararray, argv[1], sizeof(chararray) - 1); for (i=0;i<=3;i++){ /*1/ chararray[i]= getchar(); intarray[i]=i*i; /2/ } }
technology security

  1. for (i=0;i<=3;i++)

  2. intarray[i]=i*i;

  3. Both

  4. None

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Correct Option: A

What is the vulnerability ? int main (int argc, char *argv[]){ char k[3]; int i=0,j=1; char buffer[50]; strncpy(buffer, argv[1], sizeof(buffer) - 1); buffer[49]='/0'; unsigned char ch='a'; k[0]=1; do{ i++; k[i]=ch+i; } while(i<3); return 0; }
technology security

  1. Heap overflow

  2. Integer overflow

  3. Off by one error

  4. None

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Correct Option: C

The options show various uses of strncpy. Choose which use of strncpy is most secure while not wasting storage space at dst? Src is an untrusted input obtained from an external source.
technology security

  1. strncpy(dst,src,len(dst))

  2. strncpy(dst,src,len(src)+1)

  3. strncpy(dst,src,len(dst)+1)

  4. strncpy(dst,src,len(dst)-1)

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Correct Option: D

While trying to print an eight character long name, which of the following will introduce a security vulnerability ? printf ("%.8s",name); /* 1 / printf (name); / 2 / printf ("%s",name); / 3 / printf ("%8c", name); / 4 */
technology security

  1. printf ("%.8s",name); AND printf (name);

  2. printf (name); AND printf ("%s",name);

  3. printf ("%s",name); AND printf ("%8c", name);

  4. printf (name);

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Correct Option: B

Which of the following is a secure way to use scanf?
technology security

  1. scanf("%.8s", name);

  2. scanf("%8s", name);

  3. scanf("%8c", name);

  4. scanf("%s", name);

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Correct Option: B

Which line of the code should be deleted to remove vulnerability? int main(int argc,char* argv[]) { int ptr1=new int; if(ptr1==NULL) exit(1); int *ptr2=new int; if(ptr2==NULL) exit(1); char j; j=argv[1]; int k=atoi(j); if (j==0){ Ptr1=&k; delete ptr2; /1/ } else { Ptr2=&k; } delete ptr1; /2/ delete ptr2; /3/ return 0; }
technology security

  1. delete ptr2; (within if loop) AND delete ptr1;

  2. delete ptr1; AND delete ptr2; (outside if loop )

  3. delete ptr2; (within if loop)

  4. delete ptr2; (outside if loop )

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Correct Option: C

What will be sizeof(name) return? char *name="32000";
technology security

  1. 4 - it is the size of the pointer

  2. 5 - it is the number of characters in the string that the pointer points to

  3. 4 - it is the size when 32000 is stored as integer

  4. 1 - it is the size of a character variable

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Correct Option: A