The ESXi host SSH daemon must be configured to only use FIPS 140-2 validated ciphers.

Severity
Group ID
Group Title
Version
Rule ID
Date
STIG Version
mediumV-256449SRG-OS-000478-VMM-001980ESXI-70-000274SV-256449r959006_rule2025-02-111

Description

Use of weak or untested encryption algorithms undermines the purposes of using encryption to protect data. ESXi must implement cryptographic modules adhering to the higher standards approved by the federal government because this provides assurance they have been tested and validated.

ℹ️ Check

From an ESXi shell, run the following command: # /usr/lib/vmware/openssh/bin/sshd -T|grep ciphers Expected result: ciphers aes256-gcm@openssh.com,aes128-gcm@openssh.com,aes256-ctr,aes192-ctr,aes128-ctr If the output does not match the expected result, this is a finding.

✔️ Fix

From an ESXi shell, add or correct the following line in "/etc/ssh/sshd_config": Ciphers aes256-gcm@openssh.com,aes128-gcm@openssh.com,aes256-ctr,aes192-ctr,aes128-ctr