this post was submitted on 19 Jun 2025
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Linux

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Linux is a family of open source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991 by Linus Torvalds. Linux is typically packaged in a Linux distribution (or distro for short).

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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[–] iAmTheTot@sh.itjust.works 25 points 2 weeks ago (9 children)

By chaining legitimate services such as udisks loop-mounts and PAM/environment quirks, attackers who own any active GUI or SSH session can vault across polkit's allow_active trust zone and emerge as root in seconds.

I recognize a few of those words.

[–] ikidd@lemmy.world 13 points 2 weeks ago (8 children)

Basically it's two vulns chained; first one gives a remote user privileges that a physically present user would get, in order to do things like put a thumbdrive in and have it mount. Then that udisks privilege can be subverted to escalate that level to root. So as long as you can start a remote session, you can pull root and it doesn't even look that hard.

[–] iAmTheTot@sh.itjust.works 17 points 2 weeks ago* (last edited 2 weeks ago) (7 children)

So how would a bad actor start a remote session on my Linux pc?

Edited to add, downvoted for trying to learn is a new one for me.

[–] tasankovasara@sopuli.xyz 7 points 2 weeks ago (1 children)

The technique described here is only a concern if the 'bad actor' has access to a user account on your machine in the first place.

[–] iAmTheTot@sh.itjust.works 2 points 2 weeks ago (2 children)

Such as username and password?

[–] Nibodhika@lemmy.world 5 points 2 weeks ago

No, there are other ways to get access to your machine without needing it. In general you can classify vulnerabilities as either code execution or privilege escalation, a code execution vulnerability allows an attacker to execute code on your machine, a privilege escalation allows him to break barriers that you might have imposed on him.

For example, if you're running service X as root, and someone manages to find a way to use something on service X to execute code, they might get a reverse shell to your box and run anything there. So you might set service X to run as your user instead of root, now that vulnerability is less important because it only compromises your user, but the attacker could use this one in conjunction with the other one to gain control of your user, then escalate to become root.

If this is something you're interested in, there's a cool website called hackthebox where you have to do these sort of things for real. If you want to have an idea on how it looks, there are some excellent videos here showing walkthroughs for many of them he boxes, I recommend checking something labeled easy since these boxes can get quite complex, but it will give you a good idea of the steps attackers need to take to compromise your system

[–] tasankovasara@sopuli.xyz 3 points 2 weeks ago* (last edited 2 weeks ago)

Yes, or SSH keys or any other means of user authentication. The cool thing in this technique is that it's twofold and you (as an attacker) can cherry-pick the info given. If you walk up locally to someone's running system, you could skip the first half and go with the 'hey, can you resize this XFS image for me' bit.

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