ALMA-09-020810 - AlmaLinux OS 9 must not allow a noncertificate trusted host SSH logon to the system.

Information

SSH trust relationships mean a compromise on one host can allow an attacker to move trivially to other hosts.

Solution

Configure the AlmaLinux OS 9 SSH daemon to not allow a noncertificate trusted host SSH logon to the system with the following command:

Add the following line to "/etc/ssh/sshd_config", or uncomment the line and set the value to "no":

HostbasedAuthentication no

Alternatively, add the setting to an include file if the line "Include /etc/ssh/sshd_config.d/*.conf" is found at the top of the "/etc/ssh/sshd_config" file:

$ echo 'HostbasedAuthentication no' > /etc/ssh/sshd_config.d/40-hostbasedauthentication.conf

Restart the SSH daemon for the settings to take effect:

$ systemctl restart sshd.service

See Also

https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_CL_AlmaLinux_OS_9_V1R2_STIG.zip

Item Details

Category: CONFIGURATION MANAGEMENT

References: 800-53|CM-6b., CAT|II, CCI|CCI-000366, Rule-ID|SV-269264r1050146_rule, STIG-ID|ALMA-09-020810, Vuln-ID|V-269264

Plugin: Unix

Control ID: a1fd3c75f4597858aae00cd3e0207e75e6484096e99ff2f35b1079ae422a368b