CVE-2022-28735 Security feature bypass in GNU GRUB
Attackers can bypass Secure Boot restrictions in GRUB2 to load unverified code, compromising system integrity on shim-powered systems.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2022-28735?
CVE-2022-28735 is a medium-severity vulnerability in GNU GRUB, published on 20 Jul 2023. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
The GRUB2's shim_lock verifier allows non-kernel files to be loaded on shim-powered secure boot systems. Allowing such files to be loaded may lead to unverified code and modules to be loaded in GRUB2 breaking the secure boot trust-chain.
Which versions are affected by CVE-2022-28735?
It affects 1 product.
Products include Gnu Grub2.
How do I fix CVE-2022-28735?
Apply the vendor's patch.
Is CVE-2022-28735 being exploited?
There is no known exploitation of CVE-2022-28735 in the wild and no public exploit code.
Other vulnerabilities in GNU GRUB
- CVE-2024-56737 Memory corruption in GRUB2
- CVE-2022-28733 Integer underflow in grub_net_recv_ip4_packets
- CVE-2022-28734 Out-of-bounds write when handling split HTTP headers
- CVE-2025-61662 Grub2: missing unregister call for gettext command may lead to use-after-free
- CVE-2024-45782 Grub2: fs/hfs: strcpy() using the volume name (fs/hfs.c:382)
Sources
Also known as AZL-27551, AZL-34790, DEBIAN-CVE-2022-28735, GHSA-w8wh-9mrg-3ff5, UBUNTU-CVE-2022-28735.