this post was submitted on 18 Aug 2023
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Linux

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Distributions include the Linux kernel and supporting system software and libraries, many of which are provided by the GNU Project. Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses the name GNU/Linux to emphasize the importance of GNU software, causing some controversy.

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Almost every program that we run has access to the environment, so nothing stops them from curling our credentials to some nefarious server.

Why don't we put credentials in files and then pass them to the programs that need them? Maybe coupled with some mechanism that prevents executables from reading any random file except those approved.

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[–] ReversalHatchery@beehaw.org 21 points 1 year ago* (last edited 1 year ago) (1 children)

The environment of other processes is readable in procfs.

/proc/PID/environ

Thanks to the permissions it's read-only, and only by the user with which the process runs, but it's still bad, I think

[–] Lojcs@lemm.ee 7 points 1 year ago (2 children)

Don't all programs run as the user anyways? That changes nothing on a single user machine

[–] hansl@lemmy.ml 15 points 1 year ago (1 children)

A proper server should have one user per service.

[–] PuppyOSAndCoffee@lemmy.ml 0 points 1 year ago (2 children)

Service users generally don’t have passwords

[–] lemmyvore@feddit.nl 3 points 1 year ago (2 children)

You don't login as service users, they're just a means of taking advantage of the user separation features. They have the login shell set to /bin/false typically.

[–] yum13241@lemm.ee 2 points 1 year ago (1 children)
[–] russjr08@outpost.zeuslink.net 3 points 1 year ago

From a quick search I've just done, the major difference is that /bin/false can't return any text, the only thing it can do as specified via POSIX standards is return false.

So if you set someone's shell to /bin/nologin there can be some text that says "You're not allowed shell access", similar to what happens if you try to SSH into say GitHub.

Of course, for a service account that won't be operated by a person, that doesn't matter - so whichever one you use is just whichever the operator thought of first, most likely.

[–] PuppyOSAndCoffee@lemmy.ml 1 points 1 year ago

true dat; false trends to CVE vs nologin

[–] 30p87@feddit.de 4 points 1 year ago

Some have their own users, like gitlab