20-08-2012, 11:23 AM
Report on Linux Security
linux security.pptx (Size: 287.75 KB / Downloads: 26)
History Of Linux
Linus Benedict Torvalds writes an open-source operating system in 1991
Primary purpose is as a research project
At that time, no other open-source Unix flavors available. All are proprietary and costly.
Linux became hugely popular among the student and research community
Today it is a viable alternative for enterprise applications.
Linux Architecture
Linux Kernel – the actual code that interfaces between user applications and hardware resources
Hardware controllers – used by the kernel to interact with hardware
Operating System Services – software other than the kernel that are considered part of the OS: X Windows system, command shell
User Applications – software other than kernel and services: text editors, browsers, etc.
Key Points about Linux Kernel
It is separately distributed from user applications and other software
Uses modules, which can be dynamically loaded
For instance, support for FAT32 need not be fixed, but can be added dynamically
Kernel can be completely recompiled and unnecessary components can be removed – unlike Windows
Kernel has had buffer overflow vulnerabilities being discovered in it – very critical
Boot Security
Boot configuration is decided by LILO (Linux Loader) or GRUB (Grand Unified Boot Loader)
Check that only one OS is configured to load
If required ensure there is an entry for password= in lilo.conf
Also, ensure permissions are 600
User and Group Security
User accounts are created in /etc/passwd
Hashed passwords, password and account lockout policies are in /etc/shadow
Password and account lockout policies can be set during account creation, or with the chage command:
Minimum password age
Maximum password age
Expiry warning time
Inactive time after which account is locked out
Some future data when account will be locked out