Dimitry Andric <d...@freebsd.org> wrote: > For each incoming IP address, sshd does a reverse lookup, and if that > results in a hostname, it does another lookup of that hostname, to see > if *that* result matches the original incoming IP address. If it does > not, you get this scary warning in syslog about a "possible break-in > attempt!". > > In my opinion, this is fairly misleading, since almost always the actual > cause is badly configured DNS, a very common occurrence. In addition, > matching forward and reverse DNS records is no guarantee at all that the > incoming IP address is in any way trustworthy.
I'm not sure which version this made it into, but they actually removed this over 2 years ago. It's not in the openssh that ships with FreeBSD 11.2: | commit e690fe85750e93fca1fb7c7c8587d4130a4f7aba | Author: dtuc...@openbsd.org <dtuc...@openbsd.org> | Date: Wed Jun 15 00:40:40 2016 +0000 | | upstream commit | | Remove "POSSIBLE BREAK-IN ATTEMPT!" from log message | about forward and reverse DNS not matching. We haven't supported IP-based | auth methods for a very long time so it's now misleading. part of bz#2585, | ok markus@ | | Upstream-ID: 5565ef0ee0599b27f0bd1d3bb1f8a323d8274e29 cheers, Jamie _______________________________________________ freebsd-security@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-security To unsubscribe, send any mail to "freebsd-security-unsubscr...@freebsd.org"
