From the Editor - Security One Step at a Time
As I write this, yet another e-mail worm is spreading among non-Linux computers and incidentally filling my mailbox with “YOU HAVE A VIRUS” bounces from dumb software that somehow doesn't yet get the concept that worms forge mail. There's nothing like a worm attack that spares Linux to bring out the smug superiority in Linux users.
Cut it out. The attack path here is one step long. All that's keeping us safe is that most programs for Linux don't make it easy to run attachments from incoming mail. But combine the right vulnerability in a common desktop app with a little social engineering, and you've got a Linux worm.
Last year, the not-so-dramatically-named CAN-2003-0434 vulnerability allowed humble PDF files to run arbitrary commands as you. Linux users and distributions dealt with it quickly enough that it didn't turn into a vector for spreading a worm. With today's larger Linux user base and more desktop standardization, the next vulnerability will be a bigger risk.
Now that we've scared you, we'll cover the tools you could use to prevent not just a mail worm, but other attacks we don't know about yet. Run a local firewall and don't let programs on your company's desktops reach outside SMTP servers. Deploy exactly the firewall policy you want, on every host, with the advanced iptables advice in Chris Lowth's Kernel Korner on page 24. As you move your business apps to PHP, design them for security with Xavier Spriet's battle-tested designs on page 54.
And, make the next move in the spam wars. Deal with forgery where it starts. Although the US has essentially legalized spam, all the ISP advertising we've seen recently has used spam filtering as a selling point. Sender Permitted From, which Meng Weng Wong covers on page 62, lets you pop up out of the weeds and get mail through to customers who use strict spam filtering. SPF is a “look at me, I'm legit” measure you can deploy in a few minutes for a simple mail configuration.
Finally, in our cover story, Ibrahim Haddad and Miroslaw Zakrzewski explain a promising example of how to apply the kernel's Linux Security Module (LSM) interface to add process-level access control for telecom apps running on clusters (page 68). Developers can carry out this level of work, free of restrictions, because of the freedom that the GPL licensing consensus gives all of us. Keep your systems secure and enjoy this month's issue.
Don Marti is editor in chief of Linux Journal.
Practical Task Scheduling Deployment
July 20, 2016 12:00 pm CDT
One of the best things about the UNIX environment (aside from being stable and efficient) is the vast array of software tools available to help you do your job. Traditionally, a UNIX tool does only one thing, but does that one thing very well. For example, grep is very easy to use and can search vast amounts of data quickly. The find tool can find a particular file or files based on all kinds of criteria. It's pretty easy to string these tools together to build even more powerful tools, such as a tool that finds all of the .log files in the /home directory and searches each one for a particular entry. This erector-set mentality allows UNIX system administrators to seem to always have the right tool for the job.
Cron traditionally has been considered another such a tool for job scheduling, but is it enough? This webinar considers that very question. The first part builds on a previous Geek Guide, Beyond Cron, and briefly describes how to know when it might be time to consider upgrading your job scheduling infrastructure. The second part presents an actual planning and implementation framework.
Join Linux Journal's Mike Diehl and Pat Cameron of Help Systems.
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- Paranoid Penguin - Building a Secure Squid Web Proxy, Part IV
- SUSE LLC's SUSE Manager
- Google's SwiftShader Released
- Murat Yener and Onur Dundar's Expert Android Studio (Wrox)
- Managing Linux Using Puppet
- My +1 Sword of Productivity
- Non-Linux FOSS: Caffeine!
- SuperTuxKart 0.9.2 Released
- Parsing an RSS News Feed with a Bash Script
- Doing for User Space What We Did for Kernel Space
With all the industry talk about the benefits of Linux on Power and all the performance advantages offered by its open architecture, you may be considering a move in that direction. If you are thinking about analytics, big data and cloud computing, you would be right to evaluate Power. The idea of using commodity x86 hardware and replacing it every three years is an outdated cost model. It doesn’t consider the total cost of ownership, and it doesn’t consider the advantage of real processing power, high-availability and multithreading like a demon.
This ebook takes a look at some of the practical applications of the Linux on Power platform and ways you might bring all the performance power of this open architecture to bear for your organization. There are no smoke and mirrors here—just hard, cold, empirical evidence provided by independent sources. I also consider some innovative ways Linux on Power will be used in the future.Get the Guide