Security Engineering Flashcards
Takes place when too much data is accepted as input to a specific process.
Buffer Overflow
A countermeasure for buffer overflow.
Bounds Checking
The term for when an app does not release the memory it is using so that it is available to other apps.
Memory Leak
Name two counter measures for memory leak.
Garbage Collectors
Better code
When trying to access memory, CPU uses ____________ addresses. Applications use ______ addresses.
Physical
Logical
The ___________ acts like NAT for physical and logical memory addresses thereby providing security and efficiency.
Memory Manager
This type of memory is used for high speed write and read activities.
Cache Memory
ex. L1, L2, L3
What are two types of multitasking
Cooperative (process must voluntarily release resources)
Preemptive (OS controls how long each app can use a resource.)
What is multi-threading?
The ability to perform more than one thread (instruction set) at one time.
OS can perform multi-threading, however, multiple cores in a processor allow multi-threading at a hardware level.
What are the two types of multiprocessing and how do they differ?
Symmetric - like load balancing. Processors are handed work as needed.
Asymmetric - A processor is dedicated to a specific application or work load.
What are the two main CPU modes?
User (Problem State)
Privileged (Kernel Mode)
If the CPU needs to access some data either from memory or or from an I/O device, it sends a fetch request down the ___________ bus.
Address bus
Circuitry associated with the memory or I/O device receives a fetch request and recognizes the address the CPU sent down the address bus and instructs the memory or device to read the requested data and put it on the _______ bus.
Data bus
Special registers hold info like the program counter and the _________ , which holds different condition bits that indicate whether the CPU should be working in user mode or privileged mode.
Program Status Word (PSW)
What does “Random Access” mean in Random Access Memory?
Random Access Memory allows you to access information non-sequentially.
What is the difference between SRAM and DRAM?
Static RAM (SRAM) does not have a continuous refresh of electrons. Dynamic RAM (DRAM) the capacitors must be constantly refreshed. SDRAM is more expensive than DRAM and is typically used in cache.
Types of ROM in order
Read-Only Memory - Nonvolatile memory type.
Programmable read-only memory PROM - Only programmable one time.
Erasable programmable read-only memory EPROM - UV light needed to “flash” (erase) the memory.
EEPROM - Electronically erasable PROM, no UV light needed, but slow.
FLASH MEMORY - Easy to update (both good and bad!)
What is ASLR?
Address Space Layout Randomization. Introduced in Windows Vista (originally on OpenBSD).
Helps protect stuff in memory by making it harder to figure out where to attack it.
