| |
| |
For a long time Linux was considered as an operating system which only can be used by PC experts.
By the increasing popularity of this system this is no longer the case. The increased use of Linux is the reason why this
operating system meanwhile is also becoming a target of crackers. Some years ago the today's safety mechanisms of Linux has
been still suffcient. But for today`s security needs it takes some adaption in configuration.
Particularly the root user of a Linux system is all powerful. This user is subject to no restrictions and is privileged to do
everything on a system. If an aggressor should attain the users privileges, the entire system stands under his force.
Also different functions, like reloading of modules in the kernel during operation or the right assignment on file accesses,
offer too little protection.
Therefore it is necessary to be able to assign the mentioned rights (e.g. the application of a firewall) more in detail.
Linux does not offer this possibility according to standard. Who has once root privileges possession, also has the control of the
system.
The best first step, among other things, is to limit also the rights of a root user. This could be done by increasing security
already in the heart of a system, the kernel.
Thats the point were the employment of LIDS is recommended. LIDS is a patch, which makes serious changes in the kernel and therefore
it is able to increase the security of a system extremely. It offers the possibility of a more granulated right assignment and also
permits to reduce the unrestricted rights from root.
If an aggressor gains root-rights on a system, he nevertheless hardly can (depending upon set of rules) make changes to this.
Bachelor-Thesis, University of Applied Science Hagenberg (June 2004)
Back to publications |
|
