Read Download Online Free Now Sudo Mastery: User Access Control. For Real People (It Mastery Book 3) By Michael W Lucas [KINDLE PDF. About Me. ○ Latest tech books: Absolute OpenBSD,. DNSSEC Mastery, Sudo Mastery. ○ This class based on Sudo Mastery. Sudo Mastery User Access Control For Real People It Mastery Book 3 - [FREE] SUDO Tiene Favoritos Intimos Pdf DownloadFat ChanceGraded Questions On .
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Sudo Mastery. “It's awesome, it's Lucas, it's sudo. download it now.” – Slashdot. “ Michael W Lucas has always been one of my favorite authors because he brings . Sudo Mastery: User Access Control for Real People (ebook). Suggested This product includes PDF, mobi, and epub versions in a single zip file, all DRM-free. Mastery Book 3. Sudo Mastery User Access Control For Real People It Mastery Book 3 - [PDF] [EPUB]. Sudo Mastery User Access Control For Real People It.
He takes deep, involved subjects that you don't even know you need to know more about, and he makes them understandable. It's a good trick, and we're lucky he's turned his attention to sudo. The book clocks in at pages print version , and it's packed with information from start to finish. Lucas starts with the why and how of sudo, explaining why you need to know it and how sudo protects you.
He moves on to the syntax; it's kind of a bear at first, but Chapter 2, "sudo and sudoers", takes care of that nicely.
Have you locked yourself out of sudo with a poor edit? I have; I've even managed to do it on many machines, all at once, by distributing that edit with CFEngine. Lucas covers this in Chapter 3, "Editing and Testing Sudoers", a chapter that would have saved my butt. By the time you've added a few entries, you're probably ready for Chapter 4, "Lists and Aliases". Need to restart Tomcat as the tomcat user? There's a sudoers line for that.
I'm ashamed to admit that I didn't know this. A single escape during the processing will allow the otherwise non-privileged user to drop up to a root shell. A single memory corruption may allow the user to run unrestricted as root.
Why does the OS not protect the syscall to change system time or change password? Why did they design a system where you would need to start a frigging SUID root process to do that? It is a direct violation of the least privilege principle, one of the core security principles. In fact, they are really very much alike: In both cases you hand over the keys to the house and cross your fingers that the visitor is well behaved while he is in there.
Once the holes have been drilled, sudo and SUID roots make it extremely hard for security auditors to assess whether the security has been set up with meaningful barriers: They can not audit a resource and determine who has access to view or change it. And when doing that he must also trust that the SUID root utilities and sudo utilities are what they pretend to be, i.
It was necessitated because of an woefully inadequate security model. Rather than fixing the model like e. Many holes. Virtual machines are cheap these days, don't let untrusted users or processes onto your important server in the first place. They are also not suitable for every workload.
They offer no tamper-proofing, the only thing they guarantee is separation of concerns. So lets say you'll use a shared store, with a poorly-chosen you will only realize this later user privilege scheme that allows an attacker to wipe out your data.
Sure, backups. Now imagi. Most security vulnerabilities are in the applications themselves, eg buffer overflows, or on the client side. This adds nothing to the discussion. Just like VM's. If you can tamper with data via security vulnerabilities, there is nothing virtualization can do to help you.
Let's see some evidence where weakness in concern-separation from VMware instances or sudo glitches is a major contributor to malware mishaps these days. Well, lets see some evidence that virtualization somehow magically reduces or mitigates security problems, as you suggested.
Servers are servers, regardless of the physical infrastructure. If they get compromised, you may be screwed - regardless of it is a logic instance on some blade server or a good ol' physical server. I suppose the main vulnerability is a bit less control against insider malfeasance, and those are mostly due to configuration errors or corrupt admins.
Linux can use ACLs, they just aren't the default. Simple permissions work most of the time, only use ACLs for those rare occasions where they are needed.
I don't understand how it is broken by design? Think about how many endless pages are written about the security tools in Mac or Windows.
When it comes to the casual user, usually the distro will abstract the tool to a pretty common denominator. Much like Mac and Windows abstract the complex security layers within each of their OSes for the home user. It is broken by design because sudo protects the utility used to access the protected resource rather than protecting the resource itself. Since there are multiple SUID root uti. But I am actually convinced that everything security-relevant, which needs to be dealt with by anyone but its own authors, should have an as-small-as-possible, as-simple-as-possible and easy to comprehend and use interface, because otherwise it will most likely contribute to security disasters, just being mis-used.
Complexity, flexibility, feature-richness, these are all good attributes of software that is running within the same. It's a pretty dumb security tool. It allows you become user X if based on a few simple credentials. In fact I can list them: On top of that, you can ask it to do a few things when to assume user X's credentials like clear the environment, close a few files, log something - nothing you could not also do by running a wrapper script.
This part got my attention: And that's where I stopped, every time.
I've yet to truly understand Extended Backus-Naur Form, and my eyes would glaze over. I'm not the only one! I've always had this problem too.
At least now I know what it's called. The formatting used has never made sense to me. Thankfully, we have the internet where I can google examples when trying to learn a new command. I should clarify that I've never understood it because I've never seen it named or defined so i've been trying to figure them out on my own.
At least now I know what it's called and I can find some literature on it. Getting from Stuck to Success from site. Slashdot welcomes So, I am convinced I need help with using access control on real people. Maybe this book would be just the thing. Hi all -- I submitted this review, but it looks like something ate the link for the book. Here's where to download it:. I believe the site link gives the author a few more shekels, but he makes the most money from the first link; details from his website's page on this book.
I always get a bit of a laugh when an email comes through that a user tried to sudo su. Fortunately they haven't figured out the trick of using one of the programs with a shell escape, or even sudo bash. The scary bit is when the audit trail just disappears or they don't followup with an email asking for something.
My advice is to open two shells, and visudo in one and test changes in the other. Without closing your editor, save you changes, then go to your other shell and test them. I've had too many times when I had to ask my sysadmin to fix my system for me after I saved my changes and quit without discovering that I removed my priveleges thus keeping me from being able to undo my mistake.
It's like locking your keys in your car, and having to call a locksmith.
Follow Slashdot stories on Twitter. Check out Slashdot on Minds! Migrate from GitHub to SourceForge quickly and easily with this tool. Saint Aardvark writes "If you're a Unix or Linux sysadmin, you know sudo: And if you're like me, here's what you know about configuring sudo: Make sure you're in the wheel group. If you're a sysadmin, you need to stop people from shooting themselves in the foot. There should be some way of restricting use, right? Just gotta check out the man page And so I'd go back to putting some small number of people in the 'wheel' group, and letting them run sudo, and cleaning up the occasional mess afterward.
Fortunately, Michael W. Lucas has written Sudo Mastery: User Access Control for Real People. Sudo Mastery: This discussion has been archived.
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Book Review: More Login. Can we have it in major distros? Makes a lot of sense from a user's perspective. Share twitter facebook linkedin. Not That Bad Score: EBNF is hard? How much easier can it get than EBNF? Fine, mod it troll.
But you have to admit, mveloso walked into that one.