Access denied errors after NAS/server OS update

Adding a second NAS that is run with the insecure SMB v1 enabled is the solution many are taking. Either something like a Raspberry Pi or a Western Digital - WD networked drive is fairly cheap.

So more money for what should be done by Sonos!

Sadly choices must be made:

Keep your NAS secure and don't get your music.
Wait for Sonos to update and don't get your music until they do. (no announcement of any fix has been made)
Lower your security and get your music but risk security issues.
Add some new hardware with lower security on it and get your music.

Looking back at how long this has gone on and the people that have offered Sonos help in solving the problem I decided waiting longer wasn't an option.

Looking at the severity of the reported problems lowering my main NAS security wasn't an option.

Adding a $40 Raspberry Pi and a drive from my junk drawer got me my music while keeping my NAS safe so I went that route. It is a small fraction of what I have invested in Sonos gear and far less worrying than lowering my NAS security.

If Sonos ever gets us SMB v2 I'll have a spare Pi to play with when I move my library back to my NAS.

Thank you Stanley that is a very useful suggestion and I have an old HDD and have been looking for an excuse to try doing something with a Raspberry PI. It is extraordinary that SONOS is happy to put its customers at risk of WannaCry they need to be embarrassed into fixing this by lots of pressure from users. Lets hope they are listening but not likely based on the time taken so far.

It is extraordinary that SONOS is happy to put its customers at risk of WannaCry they need to be embarrassed into fixing this by lots of pressure from users.
While I completely agree that Sonos should update its SMB support to include versions later than v1, just for the record: the WannaCry vulnerability was already fixed in Windows months before the WannaCry exploit emerged. If folks choose to run un-patched or unsupported operating systems, they have much to worry about beyond SMB vulnerabilities. WannaCry is also a Windows-only exploit, and I don't know of any NAS devices running Windows.

Thank you Stanley that is a very useful suggestion and I have an old HDD and have been looking for an excuse to try doing something with a Raspberry PI.
There are lots of other fun Sonos things you can do once you've set up your rPi. Just as a couple of examples: AirConnect enables direct AirPlay on all of your Sonos speakers, and Sonos HTTP API allows you to use simple URLs to automate control of your Sonos system. Both are open source.