Live Ubuntu USB drives are used for the purposes of secure transactions e.g. banking, payments,etc in the absence of live CDs since the devices do not include CD or DVD-ROMs.

Since there are regular patches being published and the USB drives have limited storage, what is the best way to ensure the applications being used e.g. browser, shell, etc are updated without attempting to update the entire base?

Is there another way to perform similar tasks to reduce the attack vectors as opposed to using live Ubuntu USB drives

  • 1
    I'm having trouble seeing what problem you're trying to solve here.
    – Mark
    Commented Nov 19, 2014 at 8:03
  • what is your problem ? Do u want to protect usb drives from outside attack ? Commented Nov 19, 2014 at 9:24
  • 1
    @Mark - The first problem being updating the live USB drive when space is limited. Secondly, if that is deemed difficult, what other options are there?
    – Motivated
    Commented Nov 19, 2014 at 16:45
  • @Arun Prasanth - See my response to Mark
    – Motivated
    Commented Nov 19, 2014 at 16:46
  • In my experience, updates don't substantially increase the amount of disk space used.
    – Mark
    Commented Nov 19, 2014 at 20:52

1 Answer 1


The value of a Live USB or Live CD for secure transactions comes from the fact that they create a non-persisting in memory system based on a read only ISO image. That prevents all malware attacks to the local file system from being effective beyond the single session of the attack.

Upon reboot nothing from any previous session exists as it is all recreated again from that same read only ISO image that started previous session in memory. That fact also prevents patching of a Live USB stick. While the system might act as if it were taking a patch during the session there would be no persistent change in the media thus no updated behavior on the next boot.

You are right to want the latest browser etc. for your session so you are faced with two choices. You could update your browser every time you boot knowing it would not persist or you could periodically update your ISO image by creating a custom Ubuntu Live USB using their tools and instructions.

  • So if a Live USB is created with a partition to save files, will this not create persistent storage?
    – Motivated
    Commented Dec 13, 2014 at 6:45
  • If you routinely mount external storage or a partition on your bootable thumb drive you create a place for malware to persist and defeat the a significant portion of the Live CD/USB protection.
    – zedman9991
    Commented Dec 15, 2014 at 21:56
  • Hi, perhaps the most important "Live USB device" for purposes of secure transations is Tails (!). And there are no problem with upgrades: tails.boum.org/doc/first_steps/upgrade/index.en.html Commented Mar 15, 2017 at 15:46

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