V-239452

Discussion

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.

Check Content

Check the SSH daemon configuration for DoD-approved encryption to protect the confidentiality of SSH remote connections by performing the following commands:

Check the Cipher setting in the ssh_config file.
# grep -i Ciphers /etc/ssh/ssh_config  | grep -v '#' 

The output must contain either none or any number of the following algorithms:
aes256-ctr,aes128-ctr.

If the output contains an algorithm not listed above, this is a finding.

Expected Output:
Ciphers aes256-ctr,aes128-ctr