Data Leak: Media Sharing functionality provides two service end-points where 2nd service point is misconfigured to leak default Sharing folders without user involvement or consent
Version Details
- gnome-session 3.38.0-1
- gnome-user-share 3.34.0-2
- Distro: Arch
- $ uname -a :
Linux Juniper.home 5.8.14-arch1-1 #1 SMP PREEMPT Wed, 07 Oct 2020 23:59:46 +0000 x86_64 GNU/Linux
Summary
Hello, I reached out to the IRC about this and was asked to file a defect.
Tonight, I booted up my laptop to watch some videos served from my desktop and noticed there was a second sharing endpoint.
Worse, this endpoint appeared to be leaking sensitive information (receipts, etc.) that I keep in Documents/ and do not have shared on my Sharing settings.
I toggled sharing on and off a few times and the first time the endpoint remained (that could have been caching) and then after a brief outage where neither endpoint would come up (read: I could not watch my TV until I messed with it more) then the singular endpoint came up. In between the here and there, I only toggled the Sharing button in the Settings pane, the Media Sharing toggle in the submenu there, and cleared and reset my Folders that were being shared. This seemed to be sufficient to kick rygel back into sharing only the one endpoint and not my Documents/
I've pruned my journalctl for two systemd services starting but no such luck
[nicholas@Juniper ~]$ journalctl -xb -1 | grep -i rygel | grep -e Starting -e Stopping
Oct 15 18:54:27 Juniper.home systemd[1231]: Starting Rygel DLNA/UPnP server...
Oct 15 19:09:02 Juniper.home systemd[1231]: Stopping Rygel DLNA/UPnP server...
Oct 15 19:11:02 Juniper.home systemd[1231]: Starting Rygel DLNA/UPnP server...
Oct 15 19:56:31 Juniper.home systemd[1231]: Stopping Rygel DLNA/UPnP server...
Oct 15 19:57:18 Juniper.home systemd[1231]: Starting Rygel DLNA/UPnP server...
Oct 15 19:58:28 Juniper.home systemd[1231]: Stopping Rygel DLNA/UPnP server...
Oct 15 19:58:29 Juniper.home systemd[1231]: Starting Rygel DLNA/UPnP server...
Oct 15 20:02:35 Juniper.home systemd[1231]: Stopping Rygel DLNA/UPnP server...
Oct 15 20:03:43 Juniper.home systemd[1231]: Starting Rygel DLNA/UPnP server...
Basically by 19:09 I had noticed there was a leakage and started messing with it. That brings us about to now.
Steps to reproduce:
- Put pictures etc. in your Documents/ folder (I had tiff, png, jpg, etc.)
- Set up media sharing for a few folders -- do not share Documents/
- Power on computer with automatic sharing expected
- Take another computer and connect via VLC (or probably any client)
Expected Result
Gnome shares only what you ask it to share on one end point
Actual Result
Gnome is sharing my private data in Documents/ in a second endpoint The image above shows both endpoints. I can say with 100% certainty there was no second computer running in the house with those receipts, old memories, etc. This second end-point was from Juniper.
Cannot reproduce over here. Happened after an upgrade and now it's gone.