I work at Mullvad. (co-CEO, co-founder)
Some aspects of the described behavior are as we intended and some are not. The cause is not exactly as described in the blog post. As for mitigation, we are already testing a patch of the unintended behavior on a subset of our infrastructure. If any of you try to reproduce the blog post's findings you may get confusing results throughout the day.
We will also re-evaluate whether the intended behaviors are acceptable or not. Some of this is a trade-off between multiple aspects of privacy, and multiple aspects of user experience.
Please note that this is my current understanding, which may change. I was only made aware of this an hour ago, and most of that time was spent talking with Ops, considering what to do immediately, and writing this post.
Finally, for those of you who do security research: when you find a security or privacy issue, please consider notifying the maintainer/vendor before publishing your findings, even if you intend to publish right away.
I just want to say I absolutely love Mullvad! You guys did a fantastic job at designing a genuinely good and trustworthy (as much as possible) VPN vendor. You communicating here is just another data point towards this.
Can we have an Open Suse client.
Sorta odd you don't support one of Europe's most popular distros.
> Finally, for those of you who do security research: when you find a security or privacy issue, please consider notifying the maintainer/vendor before publishing your findings
How to report a bug or vulnerability
... we (currently) have no bug bounty program ... send an email to [email protected]
https://mullvad.net/en/help/how-report-bug-or-vulnerability / https://archive.vn/BeHhr
You really do provide a reassuring, good service -- thank you.
It's also worth stating that the client (including the cli client -- which, with a bit of work, you can get running in most situations where you'd use native wireguard) by default has a key rotation interval of I think 72 hours.
`mullvad tunnel get` will show it and `mullvad tunnel set rotation-interval <hours>` will change it. This is the preferred mitigation method of the post.
I personally don't mind having a pseudo-static IP (some other suppliers offer a static IPv4 as a feature!) as I wish to prevent network-level snooping from my ISP and governments. It's also worth stating that I think having a smaller IP space is an advantage for a privacy VPN: there are more potential users acting behind any given externally visible IP. Combined with technologies like DAITA (which effectively adds chaff to the tunnel) and multi-hop entrances and I personally think that this service really does plausibly make harder the life of those who snoop netflows all day.