I set up a quick demonstration to show risks of curl|bash and how a bad-actor could potentially hide a malicious script that appears safe.
It’s nothing new or groundbreaking, but I figure it never hurts to have another reminder.
I set up a quick demonstration to show risks of curl|bash and how a bad-actor could potentially hide a malicious script that appears safe.
It’s nothing new or groundbreaking, but I figure it never hurts to have another reminder.
The post is specifically about how you can serve a totally different script than the one you inspect. If you use
curlto fetch the script via terminal, the webserver can send a different script to a browser based on the UserAgent.And whether or not you think someone would be mad to do it, it’s still a widespread practice. The article mentions that piping curl straight to bash is already standard procedure for Proxmox helper scripts. But don’t take anyone’s word for it, check it out:
https://community-scripts.github.io/ProxmoxVE/
It’s also the recommended method for PiHole:
https://docs.pi-hole.net/main/basic-install/
The reality is a lot of newcomers to Linux won’t even understand the risks involved, it’s run because that’s what they’re told or shown to do. That’s what I did for pihole many years ago too, I’ll admit
Users are blameless, I find the fault with the developers.
Asking users to pipe curl to bash because it’s easier for the developer is just the developer being lazy, IMO.
Developers wouldn’t get a free pass for taking lazy, insecure shortcuts in programming, I don’t know why they should get a free pass on this.
I’ve been accused of “gate keeping” when I tell people that this is a shitty way to deploy applications and that nobody should do it.