ALMA-09-003650 - AlmaLinux OS 9 must force a frequent session key renegotiation for SSH connections to the server.

Information

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, nonorganization-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.

Session key regeneration limits the chances of a session key becoming compromised.

Solution

Configure AlmaLinux OS 9 to force a frequent session key renegotiation for SSH connections to the server by running the following command:

$ echo "RekeyLimit 1G 1h" > /etc/ssh/sshd_config.d/40-rekeylimit.conf

See Also

https://workbench.cisecurity.org/benchmarks/0

Item Details

Category: ACCESS CONTROL

References: 800-53|AC-17(2), CAT|II, CCI|CCI-000068, Rule-ID|SV-269120r1050610_rule, STIG-ID|ALMA-09-003650, Vuln-ID|V-269120

Plugin: Unix

Control ID: b4cabcb03775f2f52406dd5bb2608ed835c775848b414b81a06752d5733ec619