Description
If certificates that signed grub are installed into db, grub can be booted directly. It will then boot any kernel without signature validation. The booted kernel will think it was booted in secureboot mode and will implement lockdown, yet it could have been tampered. This flaw is a reintroduction of CVE-2020-15705 and only affects grub2 versions prior to 2.06 and upstream and distributions using the shim_lock mechanism.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| — | grub2 | Fixed in 2.06 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | grub | 2.06-r0 | — |
| Alpine v3.23 | grub | 2.06-r0 | — |
| Alpine v3.22 | grub | 2.06-r0 | — |
| Alpine v3.21 | grub | 2.06-r0 | — |
| Alpine v3.20 | grub | 2.06-r0 | — |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | grub | 2.06-r0 | — |
| Alpine v3.18 | grub | 2.06-r0 | — |
| Alpine v3.17 | grub | 2.06-r0 | — |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 2 (CBL-Mariner) | grub2 | 2.06~rc1-7 | — |