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
-
Wayland 1.24 Released with Fixes and New Features
Wayland continues to move forward, while X11 slowly vanishes into the shadows, and the latest release includes plenty of improvements.
-
Bugs Found in sudo
Two critical flaws allow users to gain access to root privileges.
-
Fedora Continues 32-Bit Support
In a move that should come as a relief to some portions of the Linux community, Fedora will continue supporting 32-bit architecture.
-
Linux Kernel 6.17 Drops bcachefs
After a clash over some late fixes and disagreements between bcachefs's lead developer and Linus Torvalds, bachefs is out.
-
ONLYOFFICE v9 Embraces AI
Like nearly all office suites on the market (except LibreOffice), ONLYOFFICE has decided to go the AI route.
-
Two Local Privilege Escalation Flaws Discovered in Linux
Qualys researchers have discovered two local privilege escalation vulnerabilities that allow hackers to gain root privileges on major Linux distributions.
-
New TUXEDO InfinityBook Pro Powered by AMD Ryzen AI 300
The TUXEDO InfinityBook Pro 14 Gen10 offers serious power that is ready for your business, development, or entertainment needs.
-
LibreOffice Tested as Possible Office 365 Alternative
Another major organization has decided to test the possibility of migrating from Microsoft's Office 365 to LibreOffice.
-
Linux Mint 20 Reaches EOL
With Linux Mint 20 at its end of life, the time has arrived to upgrade to Linux Mint 22.
-
TuxCare Announces Support for AlmaLinux 9.2
Thanks to TuxCare, AlmaLinux 9.2 (and soon version 9.6) now enjoys years of ongoing patching and compliance.