From 37ee05cf65bee54aaeda834aa71f115fca9324a4 Mon Sep 17 00:00:00 2001 From: David Schinazi Date: Wed, 5 Oct 2022 15:36:54 -0700 Subject: [PATCH] Rephrase downgrade window during updates --- draft-ietf-quic-version-negotiation.md | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/draft-ietf-quic-version-negotiation.md b/draft-ietf-quic-version-negotiation.md index af00ec7..581e14e 100644 --- a/draft-ietf-quic-version-negotiation.md +++ b/draft-ietf-quic-version-negotiation.md @@ -493,10 +493,10 @@ When removing support for a version: * Finally, the third step is to progressively remove support for the version from all server instances. That step updates the Acceptable Versions. - -Note that this opens connections to version downgrades (but only for -partially-deployed versions) during the update window, since those could be due -to clients communicating with both updated and non-updated server instances. +Note that, during the update window, connections are vulnerable to downgrade +attacks for partially-deployed versions. This is because a client cannot +distinguish such a downgrade attack from legitimate exchanges with both updated +and non-updated server instances. # Application Layer Protocol Considerations