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Additional Security in the Linux Kernel?
nyx asks: "Recently, I was looking for some way to improve security on my linux boxes. I found few linux patches like grsecurity, LIDS (now also as Linux Security Module), Medusa DS9.
I'm testing grsecurity (and it's ACLs) now and I'm quite satisfied with it, but I wonder, what are pros and cons of other solutions. Anybody tried them and can share his experience with us?"
"kernel were written in x86" ??
is x86 a language? You mean if the kernel were pure Assembly it would not have the problems it does because its written in C?
You know C was designed more or less as a "portable assembly language" for the PDPs. That is WHY it has the buffer-overflow type problems it does.
Morphing Software
Virtual machines are not perfect... they can be detected by the way they fragment memory and visible from ring 0 commands.
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but I would say just use a mac server instead if you want security that is by far the most secure.
The MacOS running WebStar as a server has never been exploited.
In fact in the entire securityfocus (bugtraq) database history there has never been a Mac exploited over the internet remotely.
That is why the US Army gave up on MS IIS and got a Mac with WebStar.
I am not talking about BSD derived MacOS X (which already had a couple of exploits) I am talking about Mac OS 9 and earlier.
Why is is hack proof? These reasons
1> No command shell. No shell means no way to hook or intercept the flow of control with many various shell oriented tricks found in Unix or NT
2> No Root user. All mac developers know their code is always running at root. Nothing is higher (except undocumented microkernel stufff where you pass Gary Davidians birthday into certain registers and make a special call). By always being root their is no false sense of security.
3> Pascal strings. ANSI C Strings are the number one way people exploit Linux and Wintel boxes. The mac avoids C strings historically in most of all of its OS. In fact even its roms originally used Pascal strings. As you know pascal strings are faster than C (because they have the length delimiter in the front and do not have to endlessly hunt for NULL), but the side effect is less buffer exploits.
4> Stack return address positioned in safer location than intel. Buffer exploits take advantage of loser programmers lack of string length checking and clobber the return address to run thier exploit code instead. The Mac places return address infornt of where the buffer would overrun. Much safer.
5 : Macs running Webstar have ability to only run CGI placed in correct lodirectoy cation and correctly file typed.
6> Macs never run code ever merely based on how a file is named. ",exe" suffixes mean nothing. For example the file type is 4 characters of user-invisible attributes, along wiht many other invisible attributes, but these 4 bytes cannot be set by most tool oriented utilities that work with data files. For ecxample file copy utilities preserve launchable file-types, but JPEG MPEG HTML TXT etc oriented tools are physically incapable of creating an executable file. the file type is not set to executable for hte hackers needs. In fact its even more secure than that. A mac cannot run a program unless it has TWO files. The second file is an invisible file associated with the data fork file and is called a resource fork. EVERY mac program has a resource fork file containing launch information. It needs to be present. Typically JPEG, HTML, MPEG, TXT, ZIP, C, etc are merely data files and lack resource fork files, and even if the y had them they would lack launch information. but the best part is that mac web programs and server tools do not create files with resource forks usually.. TOTAL security.
7> There are less macs, though there are huge cash prizes for craking into a MacOS based WebStar server. Less macs means less hacvker interest, butthere are millions of macs sold, and some of the most skilled programmers are well versed in systems level mac engineering and know of the cash prizes so its a moot point, but perhaps macs are never kracked because there appear to be less of them. (many macs pretend they are unix and give false headers to requests to keep up the illusion, ftp http, finger, etc).
8> MacOS source not available traditionally, except within apple, similar to Microsoft source availability to its summer interns and such, source is rare to MacOS. This makes it hard to look for programming mistakes, but I feel the restricted source access is not the main reasons the MacOS has never been remotely broken into and exploited.
Sure a fool can install freeware and shareware server tools and unsecure 3rd party addon tools for e-commerce, but a mac (MacOS 9) running WebStar is the most secure web server possible and webstar offers many services as is.
I think its quite amusing that there are over 200 or 300 known vulenerabilities in RedHat over the years and not one MacOS remote exploit hack.
not one ever.
Bastille linux is a hoax.
It doesn't secure anyting at all.