7-Zip Arbitrary File Write Vulnerability Let Attackers Execute Arbitrary Code (cybersecuritynews.com)
from kid@sh.itjust.works to cybersecurity@sh.itjust.works on 11 Aug 14:44
https://sh.itjust.works/post/43875331

#cybersecurity

threaded - newest

andyburke@fedia.io on 11 Aug 16:43 next collapse

How is a 7-zip user process able to write to system files, even if it is a symlink?

Either the security issue is outside 7-zip or this writeup doesn't make much sense.

elvith@feddit.org on 11 Aug 19:26 collapse

If you click through to the original advisory it becomes clear, why this is rated quite low: because of what you said. Quote:

An attacker may leverage this arbitrary file write to achieve unauthorized access/code execution, such as by overwriting a user’s SSH keys or .bashrc file

You can write to whatever the user has access, but that’s usually your home. To wreak havoc you need to either be lucky, or use some somewhat known files and paths that you can reasonably expect to exist - such as ~/.ssh/config or ~/.ssh/known_hosts or maybe a private ssh key. Otherwise you could add an alias to the shell profile for a command that you expect the user to run (e.g. alias ls to rm -rf ~). You could get quite creative with the last one (e.g. alias apt, dnf, zypper, etc. to any executable you want to run with sudo).

Edit: Why the fuck does Lemmy change a tilde to whatever attempt at turning it into an html tag that is?!

Appoxo@lemmy.dbzer0.com on 11 Aug 21:58 collapse

Just escape any special char with \

elvith@feddit.org on 12 Aug 04:57 collapse

Found the problem, it’s just the app Jerboa that somehow renders it strangely. Lemmy itself seems to behave fine

~/.ssh/config or ~/.ssh/known_hosts

as

<sub>/.ssh/config or </sub>/.ssh/known_hosts
woodytrombone@lemmy.world on 11 Aug 16:44 next collapse

WinRAR users, you’re not safe either. CVE-2025-8088 published a few days ago looks like it’s exploiting the same/similar pathway.

Bubs@lemmy.zip on 11 Aug 22:17 collapse

From the article about what is vulnerable:

For Linux systems, attackers need the target to be using a vulnerable 7-Zip version while extracting an archive format that supports symbolic links, such as ZIP, TAR, 7Z, or RAR files.

On Windows systems, additional requirements must be met for successful exploitation. The 7-Zip extraction process must have elevated privileges or operate in Windows Developer Mode to create symbolic links. This makes Windows systems somewhat less susceptible but not immune to the attack.

So Linux users would have to scan for symbiotic links beforehand, and Windows users just need to never run with elevated privileges, or scan beforehand if they do (I’m assuming that elevated privileges means “run as administrator”?)