How about ADD? Or COPY? Or RUN —-mount=type=bind,rw…?
Over the last ten years or so we’ve progressed from subtle-ish security holes due to memory unsafety and such to shiny tools in shiny safe languages that have absolutely gaping security and isolation holes by design. Go us.
[0] There is some serious wishful thinking involved there.
This seems to be pretty safe, according to the docs, if I understand them correctly. A bind mount can only mount "context directories" and the rw option will discard the written data, it says.
Too bad there's also:
Steal my credentials (temporarily, but still...) to access remote systems without restriction:
RUN --mount=type=ssh
RUN --network=host
RUN --security=insecureJust like real shipping containers, dangerous things inside can leak out - the isolation is not foolproof by any means, in fact if someone has the express wish of violating the isolation boundary it's barely an inconvenience.
I think this is a core reason why containers have such a horrible security track record.
They weren't made by design.
One of the large problems is that there is no "create_container(2)". There are 8? different namespaces in conjunction with cgroups that make up "containers" and they are infinitely configurable. This is problematic and a core reason why we see container escapes almost every other month. Just look at user namespaces - some people use them and some people don't, but it was just a few months ago when multiple bypasses were published for them.
In k8s as an example, if you share your PID namespace in a pod, which is a simple config option, you can arbitrarily enter other pod member FS tree with /proc/PID/root, only protected by Unix permissions.
Without seacomp, capabilities, SELinux etc... anyone who can launch a docker container can use the --privlaged flag and change host firmware or view any filesystem including the hosts root.
Focusing on namespace breakout only misses most of the attack surface.
so if you want sandboxing and proper isolation -- use a VM.
https://learn.microsoft.com/en-us/virtualization/windowscont...
There is some isolation but not complete isolation
The same risks that running an unknown container has - are had by building one.
For reference there have been quite a few CVEs related to container escape: https://www.paloaltonetworks.com/blog/cloud-security/leaky-v...
Especially ones that utilize a lot of the "CI/CD" pipeline approach.
Lots of secrets getting pulled from various different places, access to testing environments and testing databases needed for unit testing, access to systems that deploy to testing and prod environments. Sensitive code and secrets from multiple applications being used in the same servers and build infrastructure, etc.
So even if you trust containers to containerize securely (which is a bad idea in practice) there are all sorts of holes being poked in them to allow them integrate and access things. Even during building and testing.
Most security effort for most organizations involve hardening parts of production systems that are exposed to users and/or the internet. This not only involves proofing code and setting up firewalls, WAF, and such things, but also monitoring and whatnot.
That is expensive and a lot of work to do, while in build environments it tends to be more slapped together and people ignore them until something breaks.
You have similar situations with backup solutions. People need backups to secure data from corruption or deletion and protect businesses that way, but seeing them as a potential security hole isn't really thought about in the same way as running a production web server. Again it is something that just enough effort is put into to make sure it works and little attention is given to it unless it breaks.