GRUB2 (option quoting): Miscalculated buffer size when quoting options produces a heap out-of-bounds write

CVE-2021-20233Firmware, BMC & network fabriccurated

Impact

Miscalculated buffer size when quoting options produces a heap out-of-bounds write. Same outcome: pre-boot code execution and a Secure Boot bypass on a node the attacker already touched once.

Who can reach it

Local, via GRUB command line or a modified grub.cfg.

What to do

grub2 package update + reboot per node.

References

https://nvd.nist.gov/vuln/detail/CVE-2021-20233 https://access.redhat.com/security/cve/CVE-2021-20233

This entry is curated: imported from vendor advisories with machine assistance, not yet individually verified. Confirm against your vendor's advisory before acting, and report anything wrong.