Assuming a network which has absolutely no support for SSL/TLS, as rationalised by this blog post, is it possible guarantee the security of privileged operator connections?
There are already mechanisms which allow us to oper using salted password hashes, which should be unfeasible to attack.1
As I understand, traffic is routed between devices I have no control over, and those devices could trivially hijack an already established connection. Should I be concerned that any router between my IRC client at home and my server hosted in a different country could steal my authenticated, yet insecure connection, and use it to wreak havoc?
Furthermore, I'm aware that IP addresses are often allocated dynamically to home internet connections such as mine, and so my IP address might change on occasions. When such a DHCP renewal event occurs, is it possible that some other user of my ISP might be able to steal an authenticated, yet plain-text (insecure) connection?
Footnote: I've chosen to leave that there to keep previous answers relevant, but I've realised it's not really worth mentioning. If you'd like to include attacks against salted oper authentication, that would probably be a valuable discussion, but otherwise anything seemingly relevant to current IRCds that don't support SSL/TLS (such as ircu) should be fine.