Details

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.

Solution

From an SSH session connected to the ESXi host, or from the ESXi shell, add or correct the following line in ‘/etc/ssh/sshd_config’:

MaxSessions 1

Supportive Information

The following resource is also helpful.

• https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_VMW_vSphere_6-5_Y21M10_STIG.zip

This security hardening control applies to the following category of controls within NIST 800-53: Configuration Management.This control applies to the following type of system Unix.

References

• 800-53|CM-6b.
• CAT|II
• CCI|CCI-000366
• Rule-ID|SV-207629r388482_rule
• STIG-ID|ESXI-65-000028
• STIG-Legacy|SV-104089
• STIG-Legacy|V-94003
• Vuln-ID|V-207629

Source

• Tenable.com/audits