How to extract firmware of my Lenovo T480?
I want to check if my Lenovo T480 is afftected by the recent PKFail, but have no idea how to extract the bios firmware for validation. Can someone detail the steps? Thanks.
I want to check if my Lenovo T480 is afftected by the recent PKFail, but have no idea how to extract the bios firmware for validation. Can someone detail the steps? Thanks.
Bottom of that article, there are commands to run from windows and Linux to detect it. Probably easier than messing with the firmware.
Thanks for the hint. I followed and checked: safe
$ efi-readvar -v PK
Variable PK, length 983
PK: List 0, type X509
Signature 0, size 955, owner 3cc24e96-22c7-41d8-8863-8e39dcxxxxxx
Subject:
C=JP, ST=Kanagawa, L=Yokohama, O=Lenovo Ltd., CN=Lenovo Ltd. PK CA 2012
Issuer:
C=JP, ST=Kanagawa, L=Yokohama, O=Lenovo Ltd., CN=Lenovo Ltd. PK CA 2012
I can't say for certain, but I think you just have to grab the last firmware binary released for your T480 from the Lenovo website and run it through the online validator: https://pk.fail/
Tried. They only release it for Windows, or a bootable ISO, which I can't see what files are in there. I also tried getting the firmware from LVFS but I'm not sure if I done it right as non of them start with "EFI " header (which I assume that's the file I should be looking at).
An ISO is just another archive format, similar to zip, tarballs, and rar files. Most modern archive tools can open and/or extract its contents like any other archive.
Edit:
It looks like Lenovo releases their ISOs formatted as a CD image. See: https://workaround.org/article/updating-the-bios-on-lenovo-laptops-from-linux-using-a-usb-flash-stick/
Except the directory structure is totally gone. At least I can't see it with either by mounting or with archive software.
I was able to extract the img from the ISO using geteltorito as described in section 5 of this ArchWiki article. Once you mount the resulting img file, you'll end up with the same file contents achieved by running their Windows BIOS Utility through wine.
The relevant binaries appear to be under the folders, N24ET76P and N24ET76W. Both scan clean for me, for whatever that's worth:
curl -X POST -F'file=@N24ET76P/$0AN2400.FL1' https://pk.fail
{"details":{"analysis-time":"1.395106993s","hashes":{"md5":"ba73792a5fc831ca84b4cd3a21c03247","sha1":"24a5bb42d670c7705aed06588f0092ec11a32564","sha256":"b9510c73657460ae24c550b71d217a543b0fc3c30a3e081eff31d9d8f1a2bdda","sha512":"8ef6f0dcffbca05b79710b8599b1b1c926ee59185a675bc7eeede6da040c751097303ada523611271de6aaf190a597cdd6e9d5cf564d06987abcf712f61227c6"}},"status":"not-vulnerable"}
curl -X POST -F'file=@N24ET76W/$0AN2400.FL1' https://pk.fail
{"details":{"analysis-time":"1.438471526s","hashes":{"md5":"de1551b0bcc73e19375f7111def72278","sha1":"cd41f36d018f940c308a7be25a20e81bdb7e4cf2","sha256":"b3f646095e47bb94f04390c756cb4133201b1231a8b224174f10bb06bd3835f2","sha512":"55143f4903f92d88057bc9d4232b0d328e9ace36330f35fafdf0485d8bebb3f79b9fedc88ab1dec7fc04a8a3e0890887c1dd7632a2ffa397fb0917be90e3f93f"}},"status":"not-vulnerable"}
The linux command mentioned in the Ars Technica article elsewhere here is efi-readvar -v PK. For Fedora and Arch users, efi-readvar is available in the efitools package.
Edit: Clarity
It looks like Lenovo releases their ISOs formatted as a CD image. This site should get you pointed in the right direction: