CVE-2026-82018
IGEL OS 12 before 12.9.0, 12.8.3 LTS and IGEL OS 11 before 11.11.150 contain a secure boot bypass vulnerability in the GRUB boot stage that allows physically present attackers to gain unauthorized root access by placing an unsigned empty file named igel.conf on a partition. Attackers can exploit GRUB's fail-open signature verification behavior to drop into an interactive GRUB prompt, then boot the device's own kernel with additional command-line arguments to obtain a root shell with the disk unlocked while leaving TPM PCR values unaltered.
脆弱性の種類
IGEL OS 12 before 12.9.0, 12.8.3 LTS and IGEL OS 11 before 11.11.150 contain a secure boot bypass vulnerability in the GRUB boot stage that allows physically present attackers to gain unauthorized root access by placing an unsigned empty file named igel.conf on a partition. Attackers can exploit GRUB's fail-open signature verification behavior to drop into an interactive GRUB prompt, then boot the device's own kernel with additional command-line arguments to obtain a root shell with the disk unlocked while leaving TPM PCR values unaltered.
参考情報
- https://blog.amberwolf.com/blog/2026/august/thin-client-thin-crypto-overview/
- https://kb.igel.com/en/security-safety/current/isn-2026-20-grub-shell-escape-in-igel-os
- https://media.defcon.org/DEF%20CON%2034/DEF%20CON%2034%20presentations/DEF%20CON%2034%20presentations/DEF%20CON%2034%20-%20Darren%20McDonald%20-%20Thin%20Client%20Thin%20Crypto%20-%20Bypassing%20Full-Desk%20Encryption%20Across%20Three%20Major%20Thin%20Clients%20Vendors%20without%20Breaking%20a%20Ci.pdf
- https://www.vulncheck.com/advisories/igel-os-12-11-secure-boot-bypass-via-unsigned-igel-conf-file