First, the article doesn’t characterize the feature as an attack or a backdoor at all. It describes how a perfectly valid feature can be exploited to achieve deeper network penetration. I believe this technique was actually used to target Coinbase a few months back, as I recall from a post in HN a while back.

It’s useful in pivoting from a foothold attack at the boundary (e.g. Chrome zero-day) into the crown jewel backend which could be totally isolated to reduce the attack surface, but if you connect into it from a compromised host, this provides a convenient and hard to disable vector to piggyback onto the connection.

If there was no way to piggyback the session, even owning the developer’s terminal doesn’t gain you access to a secure system which has multi-factor authentication using a hardware token.