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

From Red Hat Enterprise Linux 5 Security Technical Implementation Guide

Associated with IA controls: ECSC-1

Associated with: CCI-000366

SV-37908r2_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

Fix text

Edit the SSH daemon configuration and add or edit the "Compression" setting value to "no" or "delayed". Restart the SSH daemon. # /sbin/service sshd restart

Pro Tips

Lavender hyperlinks in small type off to the right (of CSS class id, if you view the page source) point to globally unique URIs for each document and item. Copy the link location and paste anywhere you need to talk unambiguously about these things.

You can obtain data about documents and items in other formats. Simply provide an HTTP header Accept: text/turtle or Accept: application/rdf+xml.