AlmaLinux OS 9 must force a frequent session key renegotiation for SSH connections to the server.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-269120 | ALMA-09-003650 | SV-269120r1050610_rule | CCI-000068 | medium |
| 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, 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. | ||||
| STIG | Date | |||
| CloudLinux AlmaLinux OS 9 Security Technical Implementation Guide | 2025-05-22 | |||
Details
Check Text (C-269120r1050610_chk)
Verify the SSH server is configured to force frequent session key renegotiation with the following command:
$ sshd -T | grep rekeylimit
rekeylimit 1073741824 3600
If "RekeyLimit" does not have a maximum data amount and maximum time defined, this is a finding.
Fix Text (F-73052r1049131_fix)
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