The SSH daemon must not allow compression or must only allow compression after successful authentication.

From SOLARIS 10 SPARC SECURITY TECHNICAL IMPLEMENTATION GUIDE

Associated with IA controls: ECSC-1

Associated with: CCI-000366

SV-26787r1_rule The SSH daemon must not allow compression or must only allow compression after successful authentication.

Vulnerability discussion

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.

Check content

Check the SSH daemon configuration for the Compression setting. # grep -i Compression /etc/ssh/sshd_config | grep -v '^#' If the setting is not present, or set to yes, this is a finding.

Fix text

Edit the SSH daemon configuration and add or edit the Compression setting value to no or delayed.

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