The SSH daemon must limit connections to a single session.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
|---|---|---|---|---|
| V-39253 | SRG-OS-000027-ESXI5 | SV-51069r2_rule | Medium |
| Description |
|---|
| The SSH protocol has the ability to provide multiple sessions over a single connection without reauthentication. A compromised client could use this feature to establish additional sessions to a system without consent or knowledge of the user. |
| STIG | Date |
|---|---|
| VMware ESXi Server 5.0 Security Technical Implementation Guide | 2017-01-06 |
Details
| Check Text ( C-46517r2_chk ) |
|---|
| Disable lock down mode. Enable the ESXi Shell. Execute the following command(s): # grep MaxSessions /etc/ssh/sshd_config If the command returns nothing, or if "MaxSessions" is not set to "1", this is a finding. Re-enable lock down mode. |
| Fix Text (F-44232r2_fix) |
|---|
| Disable lock down mode. Enable the ESXi Shell. Execute the following command(s): # vi /etc/ssh/sshd_config Add/modify the attribute line entry to the following (quotes for emphasis only): "MaxSessions 1" Re-enable lock down mode. |