Описание
EVE Doesn't Protect Rootfs
Impact
Measured boot validates BIOS, grub, kernel cmdline, and initrd but not the entire rootfs. Thus, an attacker can create an EVE-OS rootfs squashfs image with some files modified and take out the disk and replace the existing rootfs image without that being detected by measure boot and remote attestation.
Patches
Fixed in 8.6.0 and 8.12.1-lts
Workarounds
None
Ссылки
- https://github.com/lf-edge/eve/security/advisories/GHSA-5h7v-g49c-h887
- https://nvd.nist.gov/vuln/detail/CVE-2023-43636
- https://github.com/lf-edge/eve/commit/5fef4d92e75838cc78010edaed5247dfbdae1889
- https://github.com/lf-edge/eve/commit/aa3501d6c57206ced222c33aea15a9169d629141
- https://asrg.io/security-advisories/19274
- https://asrg.io/security-advisories/cve-2023-43636
Пакеты
github.com/lf-edge/eve/pkg/grub
< 0.0.0-20220708121648-5fef4d92e758
0.0.0-20220708121648-5fef4d92e758
Связанные уязвимости
In EVE OS, the “measured boot” mechanism prevents a compromised device from accessing the encrypted data located in the vault. As per the “measured boot” design, the PCR values calculated at different stages of the boot process will change if any of their respective parts are changed. This includes, among other things, the configuration of the bios, grub, the kernel cmdline, initrd, and more. However, this mechanism does not validate the entire rootfs, so an attacker can edit the filesystem and gain control over the system. As the default filesystem used by EVE OS is squashfs, this is somewhat harder than an ext4, which is easily changeable. This will not stop an attacker, as an attacker can repackage the squashfs with their changes in it and replace the partition altogether. This can also be done directly on the device, as the “003-storage-init” container contains the “mksquashfs” and “unsquashfs” binaries (with the corresponding libs). An attacker