[Buildroot] Talos security vulnerabilities TALOS-2023-1844 / TALOS-2023-1845

From: Peter Korsgaard <peter@korsgaard.com>
To: buildroot@buildroot.org
Subject: [Buildroot] Talos security vulnerabilities TALOS-2023-1844 / TALOS-2023-1845
Date: Wed, 06 Dec 2023 09:15:45 +0100	[thread overview]
Message-ID: <87y1e7sq4u.fsf@48ers.dk> (raw)

FYI,

Talos recently reported a number of security vulnerabilities in the
package download hash checking in Buildroot, and these are now public
at:

https://talosintelligence.com/vulnerability_reports/TALOS-2023-1844
https://talosintelligence.com/vulnerability_reports/TALOS-2023-1845

A small number of packages did not have a .hash file, meaning that the
downloaded sources were not verified - And for aufs + aufs-util they
were downloaded from a http:// site, so conceptually vulnerable to a man
in the middle attack.

aufs/aufs-utils were changed to fetch from https by:

https://gitlab.com/buildroot.org/buildroot/-/commit/f2a590750f5bedcee48ce7beb8f35356b42eda11
https://gitlab.com/buildroot.org/buildroot/-/commit/99d525028f969220719a4e6bcd694f7d9cfd5b67

The fallback download location on source.buildroot.net was changed to
use https:// by:

https://gitlab.com/buildroot.org/buildroot/-/commit/05296ced369bab8877efa624f3d9b4d201ba5b38

Hash files for riscv64-elf-toolchain and mxsldr were added by:

https://gitlab.com/buildroot.org/buildroot/-/commit/58d7c712d7d1ef5b439ead455a4ed2ca659b60fb
https://gitlab.com/buildroot.org/buildroot/-/commit/fefcfddc5e6a265c66adbdff615558f99133f148

Which are all included in 2023.02.7 / 2023.08.3 / 2023.11.

Some packages allow a custom version or even a custom upstream location
(E.G. Linux, U-Boot, versal-firmware, ..). For those custom versions
Buildroot naturally cannot provide the expected hash, so instead we have
added support for providing hashes for those files in the
BR2_GLOBAL_PATCH_DIR location and added a
BR2_DOWNLOAD_FORCE_CHECK_HASHES option to enforce hash checking (and
fail if missing/invalid) for all downloads. This was added by:

https://gitlab.com/buildroot.org/buildroot/-/commit/5d36710e36fc4698c8fae71675bcff7395246006
https://gitlab.com/buildroot.org/buildroot/-/commit/e091e31831122b60b084bd755e94df4dfe7188d2

To make it easier to manage these custom hash files a
utils/add-custom-hashes helper script has been added by:

https://gitlab.com/buildroot.org/buildroot/-/commit/4984d0f230d0962270beb195966603f1d5a56300

Which are all included in 2023.02.7 / 2023.08.3 / 2023.11.

See the documentation for further details about this feature:

https://buildroot.org/downloads/manual/manual.html#_adding_project_specific_patches_and_hashes

Notice that it is up to the user of Buildroot to use this feature to
protect their custom downloads!

Finally the toradex_apalis_imx6_defconfig fetched Linux and U-Boot from
a git:// URL, so custom hashes were added in the BR2_GLOBAL_PATCH_DIR
for those by:

https://gitlab.com/buildroot.org/buildroot/-/commit/cdc9b8a3a75c4c39f23feb4e3b0e296786e0132c

Which is included in 2023.02.8 / 2023.08.4 / 2023.11.

Thanks to Talos for discovering and reporting these issues to us and to
Yann E. MORIN for implementing the custom hash logic.

-- 
Bye, Peter Korsgaard
_______________________________________________
buildroot mailing list
buildroot@buildroot.org
https://lists.buildroot.org/mailman/listinfo/buildroot