Flashcards
Buffer Overrun
Flashcards do conjunto (18)
- 1What is a Buffer Overrun?An anomaly that happens when you are writing data to a program and you overrun the buffers boundary and overwrite adjacent memory locations
- 2Why are buffer overruns a problem?Its because of poor coding practice
- 3What type of functions are most common areas of buffer overruns?String-Handling Functions
- 4When a buffer declared on a stack is overwritten by copying data larger that the buffer capacity is considered what type of overrun?Stack Overruns
- 5Where are variables declared on the stack located by?Variables declared on the stack are located next to the return address for the functions caller
- 6Unchecked user input is passed into what unchecked function to produce a stack overrun?strcpy
- 7What is the result of sending a unchecked string input into strcpy?The return address for the function gets overwritten by an address chosen by the attacker
- 8What is one way of finding out that a buffer overrun exploit is achievable?By getting a application error message which returns the letter we used to overrun the buffer
- 9What are some of the uses of using perl?Perl is a scripting language that allows to input ASCII characters into a script.
- 10What are other examples of overruns?Heap Overruns
Array Indexing Errors
Format String Bugs
Unicode Buffer Size Mismatches - 11What is the easiest method to prevent a Buffer overrun?Prevent it by validating all inputs coming into your functions
- 12What is Safe String Handling?It is the largest source of buffer overruns
- 13Why shouldn't the strcpy (char *strDestination.char*strSource) be used?It is unsafe.
it can blow up due to: source or destination being null, having source string larger than destination - 14By using this statement: If (strlen(input) < sizeof(buf) ) Which unsafe function can you make a bit safer?Strycpy. In this case you check the input buffer for proper length
- 15True or False? Sprintf() is a safe function in c++False. It is just as bad as strcpy()
- 16Strncpy(char*strDestination.char*strSource,Count) is safer than strcpy because it adds a count argument. Why is this still vulnerable to buffer overruns?This is because you can pass a count that is larger than the destinations buffer size. If the source is bigger than the buffer, you will still get a buffer overrun.
- 17What is a safe set of string handling functions?Strsafe.h; Its been implemented into the latest Microsoft compilers
- 18Visual C++ .NET/GS Options are compiler settings that prevents simple stack overruns by using ______ . This is still vulnerable to ______ stack overrunsPointers ; Difficult
Informações
- Descrição
- FlashCards sobre Buffer Overrun, criado por Shahmeran Gilani em 01-11-2017.
- Criado por
- Shahmeran Gilani
- Visualizações
- 8
- Avaliação