oss-sec mailing list archives
Re: Re: lockdown bypass on ubuntu 18.04's 4.15 kernel for loading unsigned modules
From: Marcus Meissner <meissner () suse de>
Date: Mon, 20 Jul 2020 18:32:34 +0200
Hi, This has gotten assigned CVE-2019-20908. Ciao, Marcus On Mon, Jun 15, 2020 at 05:09:51PM -0700, Reed Loden wrote:
Please use https://cveform.mitre.org/ to request a CVE directly from MITRE. That’s your quickest and best way. :-) ~reed On Mon, Jun 15, 2020 at 4:02 PM Jason A. Donenfeld <Jason () zx2c4 com> wrote:Hi Mitre, People are requesting a CVE to track this and are poking me to poke you to assign one. Jason On Sun, Jun 14, 2020 at 12:30 AM Jason A. Donenfeld <Jason () zx2c4 com> wrote:Hey folks, I noticed that Ubuntu 18.04's 4.15 kernels forgot to protect efivar_ssdt with lockdown, making that a vector for disabling lockdown on an efi secure boot machine. I wrote a little PoC exploit to demonstrate these types of ACPI shenanigans:https://git.zx2c4.com/american-unsigned-language/tree/american-unsigned-language.shThe comment on the top has description of exploit strategy and such. I haven't yet looked into other kernels and distros that might be affected, though afaict, Canonical's kernel seems to deviate a lot from upstream. Jason
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- Re: Re: lockdown bypass on ubuntu 18.04's 4.15 kernel for loading unsigned modules Marcus Meissner (Jul 20)