Post Syndicated from jzb original https://lwn.net/Articles/1096200/

The Radicle peer-to-peer
code-collaboration project has disclosed
two critical vulnerabilities in the network protocol used by Radicle
nodes. The first flaw is that the network protocol used by Radicle “does not
give the confidentiality it was expected to give“, which allows anyone who
can observe the network between two nodes to read the data exchanged. The second
is that peer authentication is broken and allows impersonation, so an attacker
can spoof their Node ID and read private repositories they should not be able to
read.

In practice, the two flaws are most useful when they can be exploited
together: an attacker on the path sees the Node IDs at both ends of a
connection, and both are normally on the allow-list. That attacker can read
whatever is exchanged while they watch, and can then use a Node ID they saw to
fetch the whole repository on demand. The realistic threat is anyone on the path
between your node and node it syncs with, and no setting or allow-list protects
against them.

We are publishing this before the security update is available. You can act
on it today, and no fix we release later can undo an exposure that has already
happened.

See the post for workarounds that can be used today; a major update that will
be backward-incompatible is underway.