AlmaLinux OS 9 must force a frequent session key renegotiation for SSH connections to the server.
Severity | Group ID | Group Title | Version | Rule ID | Date | STIG Version |
|---|---|---|---|---|---|---|
| medium | V-269120 | SRG-OS-000033-GPOS-00014 | ALMA-09-003650 | SV-269120r1050610_rule | 2025-02-20 | 1 |
| 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. |
| ℹ️ Check |
|---|
| 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 |
|---|
| 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 |