OpenSSH issue: 14-Current rejects non-publickey scp/ssh/rsync connectiosn all of the sudden

From: FreeBSD User <>
Date: Thu, 09 Sep 2021 19:15:03 UTC

after upgrading 14-CURRENT to recent sources September, the 8th 2021, we realizes today a
strange non-standard behaviour when connecting attempts from several clients to 14-CURRENT
based machines were made involving sshd.

First discovered on 13-STABLE clients (NanoBSD, router/fw appliance). With non-public-key
authentication we copy the config partition tar'ed over to a backup system. This worked great
until yesterday. Today the connection is dropped immediately, /var/log/auth.log (sshd log on
14-CURRENT) states:

Sep  9 19:19:10 <4.6> thor sshd[1350]: Failed password for user01 from port
24332 ssh2

A usual ssh login attempt also fails this way:
Permission denied, please try again.

The same behaviour is to observe with Xubuntu 20.04 clients and several other FreeBSD
13.0-RELENG and 13-STABLE clients. Also 14-CURRENT-to-14-CURRENT connection attempts are

The only working scheme right now is public key authentication and that is for some scenarios
not applicable.

What has changed in the recent 14-CURRENT OpenSSH update that dramatically that working
schematics do not work any more?

By the way, on the target host's sshd, on all instances,

settings like these

PasswordAuthentication yes
ChallengeResponseAuthentication yes
UsePAM yes

are set explicitely, while "UsePAM" produces an error:

/etc/ssh/sshd_config line 89: Unsupported option UsePAM

this sound ridiculous, since the usage of that tag is documented in the man page as well as
present in the example sshd_config and set yes by default.

What is wrong here? How can the sshd issue be fixed?

Kind regards and thanks in advance,

O. Hartmann

O. Hartmann