Android VPN IP Leak Even If Always-On VPN Enabled

22 points
1/21/1970
19 hours ago
by birdculture

Comments


ptrl600

"PERMISSION_SYSTEM" meaning you can bypass the VPN, with no option to override from the user, looks broken by design to me.

14 hours ago

[deleted]
18 hours ago

MrFinch

Honestly not sure if Proton or anyone else can fix this client-side on Android. Stuff like this is why people end up moving the VPN to the router.

15 hours ago

1vuio0pswjnm7

"I reported this through the Android VRP. Apparently, it is not in their threat model."

According to Netguard logs UID 1000 "Dynamic System" appears to try to use the tunnel in an earlier Android version

Blocking UID 1000 connections, and blocking QUIC, has not caused any problems for me

Yet another example of the relative lack of user control, privacy, etc. in corporate mobile OS

Not to mention undesired "side effects" of default use of QUIC

18 hours ago

1vuio0pswjnm7

Neither Netguard nor PCAPDroid requires a "rooted device"

Personally I do not rely solely on apps to block connections/protocols. While they may work to some extent for such purposes, they can also be useful for port forwarding, logging and packet captures with trailers/extensions

To block connections and protocols I set the device gateway to a computer running a non-corporate OS compiled by the user where the user can operate firewalls, DNS, etc. No "rooted device" needed

However... If VPN settings in corporate mobile OS such as Android can be undermined via Android "updates", as shown by this example, then it stands to reason that Network settings for a network interface such as gateway, DNS, etc. could also be undermined by "updates"

With respect to user control, privacy, etc., corporate mobile OS all suck. IMHO they will continue to suck even more as the years go by, as history has shown so far. The vendors' and users' interests on these issues are not aligned, they are in conflict with each other

16 hours ago

1vuio0pswjnm7

re: "mitigation"

"device_config values persist across reboots, but a Factory Reset clears them, and a future Mainline update from Google could remove the chicken-out flag entirely. Treat this as a current-release mitigation, not a permanent one."

Life has three certainties: death, taxes and "updates" from so-called "tech" companies

14 hours ago

pogue

Do you need a rooted device to block those connections/protocols?

17 hours ago

n0thing3

Nope, mitigation below just requires adb connection

15 hours ago

pogue

Would that be an appropriate mitigation for this issue though, preventing IP leaks?

I use Windscribe vpn and it has an option for a split tunneling of apps, so I have a bunch of apps I just let through. But, when I use the 'block connections without VPN' in always on VPN, it blocks those tunneled apps.

14 hours ago

[deleted]
17 hours ago