Technology

59593 readers

2960 users here now

This is a most excellent place for technology news and articles.

Our Rules

Follow the lemmy.world rules.
Only tech related content.
Be excellent to each another!
Mod approved content bots can post up to 10 articles per day.
Threads asking for personal tech support may be deleted.
Politics threads may be removed.
No memes allowed as posts, OK to post as comments.
Only approved bots from the list below, to ask if your bot can be added please contact us.
Check for duplicates before posting, duplicates may be removed

Approved Bots

founded 1 year ago

MODERATORS

497

Novel attack against virtually all VPN apps neuters their entire purpose (arstechnica.com)

submitted 6 months ago by jeffw@lemmy.world to c/technology@lemmy.world

134 comments fedilink hide all child comments

you are viewing a single comment's thread
view the rest of the comments

[–] MonkderDritte@feddit.de 17 points 6 months ago* (last edited 6 months ago) (2 children)

If i get this right, that attack only works before the tunnel is initiated (i.e. traffic encrypted), if the hosts is compromised, right? No danger from untrusted points inbetween, right?

[–] NeatNit@discuss.tchncs.de 22 points 6 months ago (1 children)

This technique can also be used against an already established VPN connection once the VPN user’s host needs to renew a lease from our DHCP server. We can artificially create that scenario by setting a short lease time in the DHCP lease, so the user updates their routing table more frequently. In addition, the VPN control channel is still intact because it already uses the physical interface for its communication. In our testing, the VPN always continued to report as connected, and the kill switch was never engaged to drop our VPN connection.

Sounds to me like it totally works even after the tunnel has started.

[–] Natanael@slrpnk.net 2 points 6 months ago (1 children)

Yeah, it's like a fake traffic cop basically, sending your (network) traffic down the wrong route

[–] KairuByte@lemmy.dbzer0.com 1 points 6 months ago (1 children)

More like a corrupt traffic cop. There are reasons you might want this kind of functionality, which is why it exists. Normally you can trust the cop (DHCP server) but in this case the cop has decided to send everyone from all streets down to the docks.

[–] Natanael@slrpnk.net 1 points 6 months ago (1 children)

These types of attacks would likely be implemented via DHCP spoofing / poisoning, unless you're on a malicious network

[–] KairuByte@lemmy.dbzer0.com 1 points 6 months ago

I’d think the place most people use VPN is public wifi, unless they are utilizing workplace VPN.

[–] DreamlandLividity@lemmy.world 13 points 6 months ago* (last edited 6 months ago) (2 children)

No, it works at any point and the local network needs to be compromised (untrusted), the host can be secure.

So it is likely not an issue at your home unless you have weak Wi-Fi password. But on any public/untrusted Wi-Fi, it is an issue.

[–] MonkderDritte@feddit.de 2 points 6 months ago (1 children)

Yikes

[–] DreamlandLividity@lemmy.world 2 points 6 months ago* (last edited 6 months ago)

That being said, it apparently does not affect Mullvad apps on any platform other than iOS (Apple does not allow fixing it on iOS). I suspect other serious VPNs are also not vulnerable outside iOS, since it is prevented by simple leak prevention mechanism.