Even after removing insecure MAC, able to ssh to the system.

Issue

• Even if the MACs is disabled on the target system, ssh login is possible.

[root@target-system ~]$ cat /etc/ssh/sshd_config
<<snip>>
Ciphers chacha20-poly1305@openssh.com,aes128-gcm@openssh.com,aes256-gcm@openssh.com,aes128-ctr,aes192-ctr,aes256-ctr
MACs umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1   ###<< removed umac-64-etm@openssh.com
<<snip>>

[system@myhost]$ ssh -oMACs=umac-64-etm@openssh.com -l testuser target-system
Last login: Wed Jul  5 10:25:12 2023 from 10.214.240.86
[testuser@target-system ~]$