<story><title>SSH Agent Restriction (new in OpenSSH 8.9)</title><url>https://www.openssh.com/agent-restrict.html</url></story><parent_chain></parent_chain><comment><author>runlevel1</author><text>My need for agent forwarding has almost completely vanished since `ProxyJump` was added a few years ago.&lt;p&gt;&lt;pre&gt;&lt;code&gt;  Host *.example.com
    User runlevel1
    IdentityFile ~&amp;#x2F;.ssh&amp;#x2F;id_rsa-foo
    ProxyJump foo@jump.example.com
&lt;/code&gt;&lt;/pre&gt;
So when I SSH to &lt;i&gt;qux.example.com&lt;/i&gt;, it first SSHs to &lt;i&gt;foo@jump.example.com&lt;/i&gt; then through it to &lt;i&gt;runlevel1@qux.example.com&lt;/i&gt; and my agent is used on each individually.&lt;p&gt;So there&amp;#x27;s no ssh-agent socket on the intermediate jump box.&lt;p&gt;EDIT: More examples here: &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;en.wikibooks.org&amp;#x2F;wiki&amp;#x2F;OpenSSH&amp;#x2F;Cookbook&amp;#x2F;Proxies_and_Jump_Hosts&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;en.wikibooks.org&amp;#x2F;wiki&amp;#x2F;OpenSSH&amp;#x2F;Cookbook&amp;#x2F;Proxies_and_J...&lt;/a&gt;&lt;p&gt;EDIT2: For folks stuck on older SSH clients, you can do this with `ProxyCommand ssh -W ...` instead (also shown in the previous link) which is actually what ProxyJump is doing under-the-hood anyhow. &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;github.com&amp;#x2F;openssh&amp;#x2F;openssh-portable&amp;#x2F;blob&amp;#x2F;d9dbb5d&amp;#x2F;ssh.c#L1233&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;github.com&amp;#x2F;openssh&amp;#x2F;openssh-portable&amp;#x2F;blob&amp;#x2F;d9dbb5d&amp;#x2F;ssh...&lt;/a&gt;</text></comment>
<story><title>SSH Agent Restriction (new in OpenSSH 8.9)</title><url>https://www.openssh.com/agent-restrict.html</url></story><parent_chain></parent_chain><comment><author>staticassertion</author><text>Another thing that would be extremely helpful is improved logging. If the ssh-agent logged the entity that was attempting to hijack the connection it would be pretty easy to write detection logic for weird shit.&lt;p&gt;We&amp;#x27;ll probably publish about this in the next few months, my colleague added some logging and we wrote ~10 detections on the process tree + IPC signatures. It makes the entire attack extremely dangerous for an attacker.</text></comment>