Vulns, Threats, CounterMeasures Flashcards
Processor
CPU. Governs all major operators.
Multi-tasking
Processor Execution Type. Handling 2+ tasks simultaneously, more simulation
Multi-processing
System with more than one processor (CPU) to complete the execution of a single application.
Processor Execution Types
Multi-tasking
Multi-processing
Multi-threading
Multi-programming
SMP / MPP
Multi-processing
Symmetric multiprocessing: single computer with multiple processors treated equally, controlled by single OS
Massively parallel processing: tons of processors, each with dedicated resources
Multi-programming
Similar to multi-tasking. OS coordinates pseudosimultaneous execution of two tasks on a single processor
Batch/serialize multiple processor
Multi-threading
Multiple concurrent tasks to be performed within a single process.
Single State/Multi State (processing types)
Single: a processor/system only handles one level of security/data. Policy.
Multi-state: can handle multiple levels of security by leveraging protection mechanisms.
Protection Rings
L0: OS Kernel/Memory
L1: OS components
L2: Drivers, protocols, etc.
L3: User / programs, application (user mode)
mediated access model
Process States
Ready Waiting Running Supervisory Stopped
Security Modes
Dedicated
System High
Compartmented
Multilevel
Valid Sec Clearance
Access approval for all info processed by system
Valid NTK
Operating Modes
User Mode
System Mode
Read-only memory
ROM. Can’t be altered.
PROM
Programmable ROM. User can burn in contents later.
EPROM
erasable PROM. EEPROM, UVEPOM
Flash memory
Derivative of EEPROM. NAND flash, used in memory cards, thumb drives, mobile devices, SSDs
RAM
Random access memory. Readable/writeable memory that CPU uses during processing.
Only exists when power on. Temp storage.
Real memory
Main/primary memory. Largest RAM storage on computer. Dynamic RAM
Cache RAM
Taking data from slower devices and temporarily loading it in faster devices for high repeat use.
Dynamic vs static ram
Dynamic: capacitors. CPU must spend time refreshing contents to ensure integrity.
Static: flip-flop. More costly, much faster.
Registers
Onboard memory on CPU, directly accessible data to ALU (arithmetic logical unit)
Register Addressing
“Register 1”
Immediate addressing
“Add 2 to register 1”
Direct addressing
CPU is given actual address of memory location
Indirect addressing
Memory address points to intermediate memory address of actual locatino
Memory Addressing
Register Immediate Direct Indirect BaseOffset
Secondary Memory
Magnetic, optical, flash-based media/other that contain data not available to CPU.
Much cheaper.
Virtual Memory
type of secondary memory.
Pagefile is most common. Paging - brings data from disk back into real memory
Memory security issues
Proper erasure
Theft
Freezing
Access data stored in memory while in use
Primary vs secondary storage
Primary storage = primary memory == RAM.
Secondary storage = secondary memory = .. all
Volatile vs non-volatile
How likely it is to lose data when power is off
Random vs sequential
Random: can access any data wherever whenever.
Storage Media security
Data Remanence
SSD sanitization
Theft
Access to data
Phreaking
Van eck phreaking - TEMPEST. Getting monitor data from afar
Modems
Suck. remove them.
Memory-mapped I/O
Indirect mapping between CPU addresses and actual address.
Interrupt IRQ
Device sends signal on assigned IRQ. OS must control access to IRQs
Direct memory access
DMA, DACK. OS brokers once, CPU gets out of way. Devices exchange data with real memory directly.
Firmware
software stored on ROM chip.
BIOS
Basic input/output system. Independent instructinos that a computers needs to start up and load the OS from disk.
BIOS
Basic input/output system. Independent instructinos that a computers needs to start up and load the OS from disk.
phlashing
malicious code embedding itself into BIOS/firmware.
Applets
Mini programs sent from server to a client. But expose client to remote-send code to be executed
Java
ActiveX
Local Cache issues
ARP Poisoning DNS cache poisoning HOSTS file Authorizing DNS attacks Cache DNS server attacks DNS query spoofing Temporary internet files
Database security
Aggregation Inference Data Mining Data Warehousing Data Analytics
Mobile Device Security
Device security: encryption, remote wiping, lockout, screen locks, GPS, app control, storage segmentation, asset tracking, inventory control, MDM, device access control, removable storage, disabling unused features
App Sec
Key mgmt, Cred mgmt, Auth, geotagging, encryption, app whitelisting
BYOD concerns
data ownership, support ownership, patch mgmt, av mgmt, forensics, privacy, on/off boarding, adherence to corporate policies, user acceptance, legal concerns, camera/videos
