Follow @Openwall on Twitter for new release announcements and other news
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20240411140654.GA24980@openwall.com>
Date: Thu, 11 Apr 2024 16:06:54 +0200
From: Solar Designer <solar@...nwall.com>
To: oss-security@...ts.openwall.com
Subject: Re: New Linux LPE via GSMIOC_SETCONF_DLCI?

On Thu, Apr 11, 2024 at 10:32:59AM +0200, Dr. Christopher Kunz wrote:
> on a freshly installed and fully updated default Debian 12 VM (from the 
> current netinst iso), the first two exploits yield different results.
> 
> >PoC and writeup are here: 
> >https://github.com/YuriiCrimson/ExploitGSM/tree/main
> 
> This, let's call it "Yurii's version", works as advertised:
> 
> $ ./ExploitGSM debian
> kallsyms restricted, begin retvial kallsyms table
> detected kernel path-> /boot/vmlinuz-6.1.0-18-amd64
> detected compressed format -> xz
> Uncompressed kernel size -> 65902908
> successfully taken kernel!
> begin try leak startup_xen!
> startup_xen leaked address  -> ffffffff8c86f1c0
> text leaked address         -> ffffffff8a800000
> lockdep_map_size     -> 32
> spinlock_t_size      -> 4
> mutex_size           -> 32
> gsm_mux_event_offset -> 56
> Let go thread
> We get root, spawn shell
> root@...ianexploitgsm:/root# id
> uid=0(root) gid=0(root) groups=0(root)

There are two exploits in Yurii's repo above, according to Yurii for two
different bugs.  The above is one of them.  Perhaps also try the other?

> With regards to Yurii's PoC, I'd say that this can indeed be classified 
> as a working 0day LPE in the default configuration.
> 
> We don't have a CVE for this yet, do we?

I don't know, and apparently it'd need to be two CVEs for two bugs that
Yurii exploits.

Besides the already mentioned CVE-2023-6546, there is:

CVE-2023-52564: Revert "tty: n_gsm: fix UAF in gsm_cleanup_mux"
https://lists.openwall.net/linux-cve-announce/2024/03/02/54

The fixes for both CVE-2023-6546 and CVE-2023-52564 are in
gsm_cleanup_mux(), but they seem to be different changes in there.

Maybe CVE-2023-52564 is one of the bugs Yurii exploits, or maybe not.
I didn't look into this closely enough to tell.

Alexander

Powered by blists - more mailing lists

Please check out the Open Source Software Security Wiki, which is counterpart to this mailing list.

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.