Computer Memory Types and Management

A type of memory that retains data even after the power is turned off. Examples include ROM (Read-Only Memory), which stores firmware, and flash memory, used in USB drives and SSDs.

A type of memory that loses its data when the power is turned off. Examples include RAM (Random Access Memory) and SRAM (Static RAM).

A form of memory used by the CPU to quickly access frequently used data. This memory is much faster than main memory (RAM) but smaller. It usually stores instructions and data from the most recently used parts of the program.

A type of volatile memory used as the main memory in a computer. It is faster than secondary storage (like hard drives), but data is lost when the power is turned off.

A type of volatile memory, similar to RAM but faster, often used as a cache for the CPU or its registers.

An address that represents a location in a computer's virtual memory space. This address is used by the processor when accessing data or instructions.

An address that corresponds to a physical location in the computer's main memory (RAM). This is the actual address used by the memory controller to access data.

A component within the CPU that translates virtual addresses (used by the processor) into physical addresses (used by the memory controller) to access data.

DMA (Direct Memory Access) is a hardware component that directly transfers data between RAM and peripherals without CPU involvement.

The CPU accesses data in RAM using virtual addresses, which are then translated to physical addresses by the memory management unit (MMU).

Embedded systems typically use ROM (Read-Only Memory) for storing programs and data that rarely change.

The cache within a CPU accesses SRAM (Static RAM) using physical addresses.

The Translation Lookaside Buffer (TLB) is a cache that stores recently used virtual-to-physical address mappings, speeding up access time.

If a virtual address is not found in the TLB, the MMU checks the page table to find the corresponding physical address.

A page fault occurs when the requested data is not in RAM and needs to be loaded from disk.

A cold boot attack exploits the persistence of data in RAM after a system is powered off to extract sensitive information.

Cold boot attacks are a type of side-channel attack, where attackers exploit system characteristics beyond the intended functionality.

An attacker could physically access and steal a device or read data from RAM and store it externally.

The possibility of extracting the firmware by gaining physical access to the ROM where it's stored.

An attack that analyzes power consumption of the SRAM to identify specific cache contents.

Full disk encryption protects data when the system is off, but once the system is on and logged in, the data is decrypted, making it vulnerable to attacks.

The attacker can bypass virtual memory protections by using DMA and inject malicious data into RAM.

A malicious tool can attach to a running process, scan its memory, and potentially extract sensitive information like passwords.

The attacker's ability to read and write to memory like any other process after logging in, even if the entire storage device is encrypted.

The attacker can physically access and modify the firmware residing in the ROM.

To mitigate physical access-based attacks, it's generally recommended to not leave hardware unattended.

A type of memory protection mechanism that uses a table to control which devices are allowed to access specific parts of RAM. It aims to prevent unauthorized devices from directly accessing and manipulating memory, enhancing system security.

A software error that occurs when a program writes data beyond the allocated buffer, overwriting adjacent memory locations. This can cause unpredictable behaviour or even security exploits.

A security feature that prevents the execution of code from memory regions designated as non-executable, typically the stack. This helps mitigate attacks that aim to execute malicious code within the stack.

A technique used by attackers to execute malicious code without directly injecting their own code. It involves chaining together existing code fragments, called "gadgets", within a program to achieve harmful actions.

A security technique that helps prevent attackers from predicting the location of code in memory by randomly placing parts of a program in different memory addresses. This hinders attackers' ability to find and exploit vulnerabilities.

A code segment that ends with a "return" instruction, often used in Return-Oriented Programming attacks. These gadgets are found within existing code and are executed as parts of a malicious sequence built by the attacker.