Tag: technology

Questions Related to technology

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

Will following program execute successfully ? int main(int argc,char* argv[]){ int *ptr=new int; if(ptr==NULL) exit(1); char *j; for(int i=1;i<=4;i++) { j=argv[i]; int k=atoi(j); if (k!=0){ *ptr=k; delete ptr; } } }
technology security

  1. Program works when there is only 1 argument with program

  2. Program works when there are 3 arguments with program

  3. Program works when there are 4 arguments with program

  4. Program never executes successfully

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Correct Option: D

With the size of unsigned integers being 4 bytes, What happens when a negative number is entered? unsigned int i; scanf("%u",&i);
technology security

  1. A run-time error is encountered and the program aborts

  2. unsigned int variables cannot store the sign (+ or -) of the number. The sign is discarded and only the number is stored in i

  3. A large positive number will be stored in i

  4. Unsigned int variables cannot store signed numbers. Hence in this program i will contain garbage values.

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Correct Option: C

What is the value of j (size of integer is 4 bytes)? int i=987987987; int j= i*10;
technology security

  1. 1289945278

  2. garbage. Integer j cannot hold such large values

  3. 9879879870

  4. Program is aborted

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Correct Option: A

The application is receiving input from an external source. Which of the following external sources can be considered safe?
technology security

  1. Shell environment variables

  2. Data received via encrypted network channels

  3. argv[0] can only have either null or program name

  4. no external input must be trusted

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Correct Option: D

In the following code snippet, how to handle pointer? int main (int argc, char argv[]) { char j; j=argv[1]; int k=atoi(j); /delete here/ return 0; }
technology security

  1. delete j;

  2. realloc j;

  3. free j;

  4. It need not be deleted

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Correct Option: D

Code is vulnerable to buffer overflow attack and
technology security

  1. DNS Spoofing

  2. Command Injection

  3. Path Traversal

  4. Command Injection AND Path Traversal

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Correct Option: D

What can go wrong in following code? #include int main(int argc, char *argv[]){ if(argc != 3){ printf("usage: %s [source] [dest]\n", argv[0]); exit(1); } char buffer1[5]; strcpy(buffer1, argv[1]); char buffer2[5]; strcpy(buffer1, argv[1]); char x; FILE *file[2]; file[0] = fopen(buffer1,"r+"); file[1] = fopen(buffer2,"w+"); for(x = 0; x < 2; x++){ if(file[x] == NULL){ printf("error opening file.\n"); exit(1); } } do { x = fgetc(file[0]); fputc(x,file[1]); } while(x != EOF); for(x = 0; x < 2; x++) fclose(file[x]); return 0; }
technology security

  1. XSS

  2. Arc Injection

  3. Buffer Overflow

  4. Arc Injection AND Buffer Overflow

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Correct Option: D