Arch Linux

AcousticBruce

Member

Registered: 2015-03-03

Posts: 64

[SOLVED] Easy security breach?

I have Arch Linux successfully booting up without live cd. However, I lost the password (because I was playing around the other day) and I thought to myself.

What if I put live iso back in.
Mount the correct parition to /mnt
arch-chroot into /mnt
then run the passwd command.

Sure enough i changed the password. Booted back into Arch Linux and I was able to log into the root user.

I am currently studying groups and users and this just makes me wonder. Can I always just run the live iso and arch-chroot to run the passwd command? That just seemed crazy because I didnt think it would let me do that.

Last edited by AcousticBruce (2015-05-22 19:13:49)

Trilby

Inspector Parrot

Registered: 2011-11-29

Posts: 29,560

Website

Re: [SOLVED] Easy security breach?

You don't even need the live-cd/usb.  Just use the kernel parameter "break=postmount" or an equivalent.

Users and groups provide absolutely no security against someone who has physical access to the machine (and the ability to power it on/off and/or remove harddrives).  If you want that level of security, look into disk encryption.

Users/group access permissions were designed under the context of many users logging in to a (frequently remote) server.  And for these purposes they work well.  But this is really all they are for.

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jasonwryan

Anarchist

From: .nz

Registered: 2009-05-09

Posts: 30,424

Website

Re: [SOLVED] Easy security breach?

If an attacker has physical access to your machine and it is not fully encrypted*, it is game over.

*Obviously, there is a category of attackers for whom this may not be an insurmountable hurdle either...

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fukawi2

Ex-Administratorino

From: .vic.au

Registered: 2007-09-28

Posts: 6,224

Website

Re: [SOLVED] Easy security breach?

Can I always just run the live iso and arch-chroot to run the passwd command?

Yep.

You could also pull the hard drive, plug it into a suitable USB adapter and mount it on any other PC or laptop that has drivers for your file system.

Physical access == game over. This is why data centers have physical security, racks lock, racks are separated by cages etc.

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Raynman

Member

Registered: 2011-10-22

Posts: 1,539

Re: [SOLVED] Easy security breach?

Wiki also points this out: https://wiki.archlinux.org/index.php/Re … t_password

Scimmia

Fellow

Registered: 2012-09-01

Posts: 11,599

Re: [SOLVED] Easy security breach?

There's a saying: physical access is root access.

nomorewindows

Member

Registered: 2010-04-03

Posts: 3,367

Re: [SOLVED] Easy security breach?

It'd be the same for a Windows machine.  Hefty, AD scheme, but take down the server and boot it from live-cd, all files are available.

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