The AIX SSH daemon must be configured to only use FIPS 140-2 approved ciphers.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-215402	SRG-OS-000033-GPOS-00014	AIX7-00-003100	SV-215402r958408_rule	2024-08-16	3

Description
Without confidentiality protection mechanisms, unauthorized individuals may gain access to sensitive information via a remote access session. Remote access is access to DoD nonpublic information systems by an authorized user (or an information system) communicating through an external, non-organization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Encryption provides a means to secure the remote connection to prevent unauthorized access to the data traversing the remote access connection (e.g., RDP), thereby providing a degree of confidentiality. The encryption strength of a mechanism is selected based on the security categorization of the information.

Description

Without confidentiality protection mechanisms, unauthorized individuals may gain access to sensitive information via a remote access session. Remote access is access to DoD nonpublic information systems by an authorized user (or an information system) communicating through an external, non-organization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Encryption provides a means to secure the remote connection to prevent unauthorized access to the data traversing the remote access connection (e.g., RDP), thereby providing a degree of confidentiality. The encryption strength of a mechanism is selected based on the security categorization of the information.

ℹ️ Check
Check the SSH daemon configuration for allowed ciphers by running the following command: # grep -i ciphers /etc/ssh/sshd_config \| grep -v '^#' The above command should yield the following output: Ciphers aes128-ctr,aes192-ctr,aes256-ctr If any of the following conditions are true, this is a finding. 1. No line is returned (default ciphers); 2. The returned ciphers list contains any cipher not starting with aes; 3. The returned ciphers list contains any cipher ending with cbc.

ℹ️ Check

Check the SSH daemon configuration for allowed ciphers by running the following command: # grep -i ciphers /etc/ssh/sshd_config | grep -v '^#' The above command should yield the following output: Ciphers aes128-ctr,aes192-ctr,aes256-ctr If any of the following conditions are true, this is a finding. 1. No line is returned (default ciphers); 2. The returned ciphers list contains any cipher not starting with aes; 3. The returned ciphers list contains any cipher ending with cbc.

✔️ Fix
Edit the "/etc/ssh/sshd_config" file and add or edit a "Ciphers" line like this: Ciphers aes128-ctr,aes192-ctr,aes256-ctr Restart the SSH daemon: # stopsrc -s sshd # startsrc -s sshd