The last time I used tails it was 1.5.1 and I noticed there have been a few updates... Is it really necessary to upgrade it? It took me en entire week to set up it up, would rather not have to do that again if it's necessary.
Do I need to do it?
Thanks
Extremely. Once the bugs in an older version are exposed by an update, they can be immediately incorporated into the bad guys (FBI / DEA / NSA) exploit tool set. That's how the FBI de-anonymized a bunch of people in the Freedom Hosting case. They used a known bug against people that hadn't updated the Tor browser to the latest version.
Make a backup of your important files / PGP keys before upgrading.
You can use this method to create an encrypted volume on a 2nd USB to copy your important info to:
https://tails.boum.org/doc/encryption_and_privacy/encrypted_volumes/index.en.html
If you are a Windows user, you can use this method to create a backup image of your Tails USB with persistence:
https://www.reddit.com/r/sohhlz/wiki/index/backup/windows-usb-image