NFS 3 and the specter of the spoof attack
Ghost on the Loose
© Snowshill, Fotolia
Host-based authentication is easy to configure, but it doesn't do much to stop uninvited guests.
The CIO of a famous credit union was fairly sure he had thought of everything: state-of-the-art antivirus tools, separate zones for desktops and servers, firewalls at strategic points, and regular operating system updates. He also favored "stable versions" of operating systems, applications, and protocols for added assurance.
Unfortunately, this CIO decided to take a short cut in setting up the file server: NFS version 3 [1] with the legacy "host-based access control" and no special hardening. Although NFS 4 has been around for several years, many networks continue to use NFS 3 because it is simpler and it is already up and running.
Ease of use is certainly an important consideration; however, in the case of NFS, this simplicity sometimes comes with a cost. The host-based scheme used with NFS 3 has several significant problems. Also, NFS 3 transmits unencrypted data blocks (see Figure 1), it only performs rudimentary authentication, and its authorization mechanisms are easily avoided (see the "NFS Security Functions" box).
[...]
Buy this article as PDF
(incl. VAT)
Buy Linux Magazine
US / Canada
UK / Australia
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters
Support Our Work
Linux Magazine content is made possible with support from readers like you. Please consider contributing when you’ve found an article to be beneficial.
News
-
Linux Kernel Project Releases Project Continuity Document
What happens to Linux when there's no Linus? It's a question many of us have asked over the years, and it seems it's also on the minds of the Linux kernel project.
-
Mecha Systems Introduces Linux Handheld
Mecha Systems has revealed its Mecha Comet, a new handheld computer powered by – you guessed it – Linux.
-
MX Linux 25.1 Features Dual Init System ISO
The latest release of MX Linux caters to lovers of two different init systems and even offers instructions on how to transition.
-
Photoshop on Linux?
A developer has patched Wine so that it'll run specific versions of Photoshop that depend on Adobe Creative Cloud.
-
Linux Mint 22.3 Now Available with New Tools
Linux Mint 22.3 has been released with a pair of new tools for system admins and some pretty cool new features.
-
New Linux Malware Targets Cloud-Based Linux Installations
VoidLink, a new Linux malware, should be of real concern because of its stealth and customization.
-
Say Goodbye to Middle-Mouse Paste
Both Gnome and Firefox have proposed getting rid of a long-time favorite Linux feature.
-
Manjaro 26.0 Primary Desktop Environments Default to Wayland
If you want to stick with X.Org, you'll be limited to the desktop environments you can choose.
-
Mozilla Plans to AI-ify Firefox
With a new CEO in control, Mozilla is doubling down on a strategy of trust, all the while leaning into AI.
-
Gnome Says No to AI-Generated Extensions
If you're a developer wanting to create a new Gnome extension, you'd best set aside that AI code generator, because the extension team will have none of that.