Open-Xchange: Recursor accepts unsigned, empty NXDOMAINs in secure zones

Hi! This is a slightly edited version of the email I sent to the project's security contacts on 2020-04-21. Open-Xchange confirmed it and asked me to resubmit it here. --- Subject: Recursor may be accepting unsigned, empty NXDOMAINs in secure zones I can easily reproduce this against Cloudflare's...