Unix Filesystem Permissions

The cluster discusses security risks and implications of write access to filesystems in Unix-like systems, including chmod commands, ownership, ACLs, nosuid mounts, and comparisons to traditional permission models.

➡️ Stable 0.7x Security
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#143
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Keywords

resolv.conf AFAIK MAC PHP pngtopdf.py GP Terminal.app freebsd.org ASAP OS permissions file user unix files permission filesystem read write write cron

Sample Comments

ciupicri Mar 19, 2015 View on HN

If someone else has write access to the your filesystem, you're already screwed.

gigatexal Jul 30, 2018 View on HN

for the noob like me, how does this compare to setting a permissions or ownership bit on a folder?

thefz Oct 18, 2022 View on HN

Does it allow you to have access to the whole fileystem, unrestricted access?

lincolnq Oct 20, 2010 View on HN

No. You have one of the workarounds the author suggests, which is only allowing users to write to nosuid mounts.

raverbashing Jun 10, 2016 View on HN

Only if they made their "backups" writable as well

afhof Feb 13, 2012 View on HN

I mean the fact that the binaries on disk can be modified without getting user permission.

adql Nov 22, 2022 View on HN

Could still use plain old filesystem permissions no ?

1_2__3 Mar 11, 2017 View on HN

Bear in mind that no it cannot write arbitrary files. It's a unix system, it has unix permissions, and required privilege escalation to write to locations the user is not allowed to.

scintill76 Sep 25, 2014 View on HN

I think it's that all files have mode 0777, i.e. executable by default. I think it can be changed with mount options though.

freemint Mar 7, 2022 View on HN

Yes it would. That is implied because writing arbitrary files means you can also edit the permission systems