The ESXi host Secure Shell (SSH) daemon must not allow compression or must only allow compression after successful authentication.
An XCCDF Rule
Description
<VulnDiscussion>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.</VulnDiscussion><FalsePositives></FalsePositives><FalseNegatives></FalseNegatives><Documentable>false</Documentable><Mitigations></Mitigations><SeverityOverrideGuidance></SeverityOverrideGuidance><PotentialImpacts></PotentialImpacts><ThirdPartyTools></ThirdPartyTools><MitigationControl></MitigationControl><Responsibility></Responsibility><IAControls></IAControls>
- ID
- SV-256390r885951_rule
- Severity
- Medium
- References
- Updated
Remediation - Manual Procedure
From an ESXi shell, add or correct the following line in "/etc/ssh/sshd_config":
Compression no