Insecure updates are the rule, not the exception
The Update Framework
As with most things in open source, you don't have to reinvent the wheel. The Update Framework (TUF) [5] is available under an open source license (but not one I recognize) and is written mostly in Python, so it's pretty understandable. Even better is that all the above security issues have been taken into account for the system design and implementation. It even addresses possible problems like key compromise.
One basic thing to keep in mind about security, especially for software updates, is that you need to make your system as secure as you can, but you also need to make it possible to return to a known good state (i.e., you have removed all the compromised packages and so on from your update infrastructure).
TUF places all of the heavy lifting on the server and end client. Thus, the intermediary mirror systems don't even need to know about it, which in turn makes deployment possible (trying to get a major mirror site to install some software so they can securely serve updates is a battle you will lose). Unfortunately, TUF isn't perfect – the only client is written in Python, so integrating it with non-Python software or on systems that don't natively support Python (e.g., Windows) will be difficult, to say the least. For more information, an excellent lightning talk is available on YouTube [6] that covers all the basics of TUF using PyPI.
Conclusion
You can certainly use TUF to secure updates, but, unfortunately, deploying TUF is nontrivial. You're going to need at least two servers (in case one fails) and some keys that will require management. That means it's probably not going to be used; in fact, I'm not aware of any software that uses TUF for updates. So, unless people start demanding that organizations and vendors, like WordPress, Drupal, Joomla, RubyGems, PyPI, Hackage, CPAN, and so on, start providing secure updates for all the code they make available, it isn't going to happen.
Kurt Seifried
Kurt Seifried is an Information Security Consultant specializing in Linux and networks since 1996. He often wonders how it is that technology works on a large scale but often fails on a small scale.
Infos
- HTP Zine 5: http://straylig.ht/zines/HTP5/0x02_Linode.txt
- Social Media Widget remote file inclusion: http://seclists.org/oss-sec/2013/q2/83
- OpenPGP Card: http://en.wikipedia.org/wiki/OpenPGP_card
- Kernel Concepts Security/Smartcards: http://shop.kernelconcepts.de/index.php?cPath=1_26
- The Update Framework: https://www.updateframework.com/
- TUF lightning talk: https://www.youtube.com/watch?v=2sx1lS6cT3g
« Previous 1 2
Buy this article as PDF
(incl. VAT)
Buy Linux Magazine
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
-
Canonical Releases Ubuntu 24.04
After a brief pause because of the XZ vulnerability, Ubuntu 24.04 is now available for install.
-
Linux Servers Targeted by Akira Ransomware
A group of bad actors who have already extorted $42 million have their sights set on the Linux platform.
-
TUXEDO Computers Unveils Linux Laptop Featuring AMD Ryzen CPU
This latest release is the first laptop to include the new CPU from Ryzen and Linux preinstalled.
-
XZ Gets the All-Clear
The back door xz vulnerability has been officially reverted for Fedora 40 and versions 38 and 39 were never affected.
-
Canonical Collaborates with Qualcomm on New Venture
This new joint effort is geared toward bringing Ubuntu and Ubuntu Core to Qualcomm-powered devices.
-
Kodi 21.0 Open-Source Entertainment Hub Released
After a year of development, the award-winning Kodi cross-platform, media center software is now available with many new additions and improvements.
-
Linux Usage Increases in Two Key Areas
If market share is your thing, you'll be happy to know that Linux is on the rise in two areas that, if they keep climbing, could have serious meaning for Linux's future.
-
Vulnerability Discovered in xz Libraries
An urgent alert for Fedora 40 has been posted and users should pay attention.
-
Canonical Bumps LTS Support to 12 years
If you're worried that your Ubuntu LTS release won't be supported long enough to last, Canonical has a surprise for you in the form of 12 years of security coverage.
-
Fedora 40 Beta Released Soon
With the official release of Fedora 40 coming in April, it's almost time to download the beta and see what's new.