Clyde's Blog

So I got hacked for the first(that I know of) and hopefully last time on a Linux box a few days ago. I hate admitting it but I figure I'd put it out there in hopes this could prevent someone else from falling victim. It was actually on one my systems at work that's a VM running on top of XEN. If any of you frequent slashdot you may have recently seen this local root exploit http://it.slashdot.org/article.pl?sid=08/02/10/2011257 The exploit affects linux kernels 2.6.17 to 2.6.24.1. If you're running ubuntu a fix has already been released for 6.10, 7.04 and 7.10 http://www.ubuntu.com/usn/usn-577-1

To carry out this local exploit the attacker would have had to already gained access to your system with any user. In my case the attacker was able to crack the password for one of my users and log in via ssh then they compiled and ran the exploit to gain root access in a matter of seconds. After which they downloaded some more stuff and my server was one of the nodes used to launched a DOS attack against some site overseas.

Of course this whole thing pains me because I can think of at least 3 obvious precautionary steps that could have prevented this from happening. The most obvious is, if a fix was released why wasn't it applied to the server? In my defense there's something about XEN that prevents you from upgrading your kernel within the VM. It seems the VM loads the kernel from the host so I had to rely on the vendor to release the fix, which they didn't in time.

Luckily this wasn't a critical server and the good thing about the hack is we now know our current weaknesses and what now needs to be done to prevent this from happening in the future. Still sucks though

VMWare is a company that developes proprietary virtualization software. They've been around since 1998 and are now the industry leader in virtualization software and appliances. Their most notable products are VMWare Workstation, GSX and ESX Server. These products aren't free but a little over a year ago they launched VMWare Server GA(General Availability) which is based on GSX Server and is free to use. I've been using it since the beta version and I must say I'm very happy with it so far. Some of you whom may have already had experience with the three non-free products might miss some features like linked cloning and shared directories between guest and hosts but it still has allot of features, its easy to use, stable and free of charge. Now I do allot testing and evaluating new software, especially client-server and network centric software. Server GA has made it so much easier for me. Its probably the best learning tool I've used to date. This blog actually runs on an Ubuntu Guest within Server GA on top of an Ubuntu Host with 2GB RAM and P4 processor. The performance isn't bad and I usually have about 3 or 4 other Guest running at the same time on this host.

Anyway enough of the VMWare overview. Download it and try it for yourself. It runs on Windows and Linux although benchmarks have shown that performance wise it runs best on Linux hosts.

There are two things I do with Server GA on a regular basis and they are creating snapshots and cloning. Snapshots are good when making a change to some software on your Guest that you might be unsure of. You can just take a snapshot of the Guest prior to the change and if everything goes haywire after the change just revert back. Its one of those features that once you use you won't know how you made major changes without it. Now unfortunately cloning a VM isn't a built out feature in Server GA..meaning you can't do it within the GUI and there's no command line utility that allows you to easily clone a VM. There is a command line utility packaged with Server GA called vmware-vdiskmanager that allows you to change the name of a virtual disk. This utility is what I've used along with a few other shell commands to fully clone a VM.

VM cloning is cool because allot of times I want to bring up an OS quickly to test some software that might need to run in its own isolated environment so what I do is keep a base pristine installation of Linux(Ubuntu Server mainly) and Windows Guests and then I run some commands to clone base install. After the process I can start the newly created VM and wallah I have a freshly installed system within 10 minutes. Anyway I wrote a script that will do this for. If you can't put the script to use for yourself you can at least read it to get an idea of how to clone in Server GA since its not apparent.

Of course when you're done cloning you'll need to Create a UUID after you start the VM and go through routine things within the OS like changing your hostname, IP and applying new updates.

Clyde

Yea I said it...I'm tired of today's Hip Hop. I no longer recognize the music. See I was fortunate to live my teenage years in what I call the "Golden Age" of rap from about 93' to 99'(maybe up to 01'). During that time the songs meant something even if they were laced with violence, drugs, sex. There was still a viable reason behind those lyrics because it told the stories of the harsh realities of living in "ghetto usa". A story that needed to be told because things got out of hand during the late 80's/early 90's when crack cocaine was and still is destroying our neighborhoods. I see those songs back then as a cry for help. Well America listened and they listened so much that Hip Hop music became, in that time, arguably the most popular genre of music in the world. Rap's popularity was a gift to those neighborhoods and likewise a curse. A curse because the big labels got a hold of it and money started pouring in. Money just has this way of contaminating. Instead of answering the cry the big labels misunderstood the music and turned it into something that glorifies the negative lifestyle and now you have what we have today. Sickening. Back in the day the culture (Hip Hop) drove the music but now its like the music drives the culture so you have these kids who think its cool to be "gangsta" or cool to be unintelligent. These kids are getting older and they're becoming the artists and producing mindless songs like "A Bay Bay" or "Superman that Ho". I just can't deal with it anymore and I never thought I'd actually say it because I hoped the music I loved would last. However Hip Hop as I knew it is Dead.