The ESXi host Secure Shell (SSH) daemon must not allow compression or must only allow compression after successful authentication.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-256390 | ESXI-70-000021 | SV-256390r959010_rule | Medium |
| Description |
| If compression is allowed in an SSH connection prior to authentication, vulnerabilities in the compression software could result in compromise of the system from an unauthenticated connection, potentially with root privileges. |
| STIG | Date |
| VMware vSphere 7.0 ESXi Security Technical Implementation Guide | 2024-12-16 |
Details
| Check Text (C-60065r885949_chk) |
| From an ESXi shell, run the following command: # /usr/lib/vmware/openssh/bin/sshd -T|grep compression Expected result: compression no If the output does not match the expected result, this is a finding. |
| Fix Text (F-60008r885950_fix) |
| From an ESXi shell, add or correct the following line in "/etc/ssh/sshd_config": Compression no |