x86 Protection Rings Model
CPU Security Layers for Privilege Separation
In x86 architecture, Protection Rings divide code execution into 4 levels (from Ring 0 with highest CPL to Ring 3 with lowest) to prevent unauthorized access to sensitive resources. This model operates via segment denoscriptors in the GDT and privilege checks (e.g., DPL).
Ring 0 (Kernel Mode):
Full access to CPU and memory; manages scheduler, paging, and interrupts. Only trusted code executes here.
Ring 1 (Driver Mode):
Medium privilege for device drivers; access to I/O ports and DMA, but limited to secure transitions.
Ring 2:
Legacy and rare; for specific execution domains.
Ring 3 (User Mode):
User applications; restricted to non-privileged instructions and system calls (via SYSCALL/INT).
@GoSecurity
#os #linux #cpu #ring_model #privilege
CPU Security Layers for Privilege Separation
In x86 architecture, Protection Rings divide code execution into 4 levels (from Ring 0 with highest CPL to Ring 3 with lowest) to prevent unauthorized access to sensitive resources. This model operates via segment denoscriptors in the GDT and privilege checks (e.g., DPL).
Ring 0 (Kernel Mode):
Full access to CPU and memory; manages scheduler, paging, and interrupts. Only trusted code executes here.
Ring 1 (Driver Mode):
Medium privilege for device drivers; access to I/O ports and DMA, but limited to secure transitions.
Ring 2:
Legacy and rare; for specific execution domains.
Ring 3 (User Mode):
User applications; restricted to non-privileged instructions and system calls (via SYSCALL/INT).
@GoSecurity
#os #linux #cpu #ring_model #privilege
👍3
X86 Memory Architecture and Memory Mapping Schemes
https://mohitmishra786.github.io/TheCoreDump/posts/X86-Memory-Architecture-and-Memory-Mapping-Schemes/
https://mohitmishra786.github.io/TheCoreDump/posts/X86-Memory-Architecture-and-Memory-Mapping-Schemes/
TheCoreDump
X86 Memory Architecture and Memory Mapping Schemes
A comprehensive exploration of x86 memory architecture and mapping schemes, covering segmentation, paging, virtual memory management, and memory protection mechanisms.
IMG_1966.JPG
466.8 KB
این تصویر یک اینفوگرافیک (infographic) است که مدل مرجع OSI (Open Systems Interconnection) را با مدل TCP/IP (Transmission Control Protocol/Internet Protocol) مقایسه میکند. این دو مدل، چارچوبهای مفهومی برای درک و پیادهسازی شبکههای کامپیوتری هستند. مدل OSI دارای ۷ لایه است و بیشتر نظری است، در حالی که مدل TCP/IP دارای ۴ لایه است و عملیتر (پایه اینترنت مدرن). جدول شامل ستونهایی برای لایههای OSI، توابع هر لایه، لایههای TCP/IP، واحدهای داده پروتکل (PDUها)، و سختافزارهای مرتبط است.
@GoSecurity
#osi #tcpip #tcp #structure
@GoSecurity
#osi #tcpip #tcp #structure
❤4
Linux-basic.pdf
822.4 KB
Linux Tutorial
This research used the ALICE High Performance Computing Facility at the University of Leicester
@GoSecurity
#linux #lpic
This research used the ALICE High Performance Computing Facility at the University of Leicester
@GoSecurity
#linux #lpic
how to use the Havoc framework and develop Beacon Object Files
https://lorenzomeacci.com/the-havoc-framework
#c2 #BOF
https://lorenzomeacci.com/the-havoc-framework
#c2 #BOF
Lorenzo Meacci
The Havoc framework | Lorenzo Meacci
In this blog post, I will demonstrate how to use the Havoc framework and develop Beacon Object Files (BOFs).