Ubuntu 23.04 LTS: USN-6410-1 Critical GRUB2 Heap Overflow and More

ubuntu

October 4, 2023

Several security issues were fixed in GRUB2.

Summary

Several security issues were fixed in GRUB2.

Software Description:

- grub2-signed: GRand Unified Bootloader

- grub2-unsigned: GRand Unified Bootloader

Details:

It was discovered that a specially crafted file system image could cause a

heap-based out-of-bounds write. A local attacker could potentially use this

to perform arbitrary code execution bypass and bypass secure boot

protections. (CVE-2023-4692)

It was discovered that a specially crafted file system image could cause an

out-of-bounds read. A physically-present attacker could possibly use this

to leak sensitive information to the GRUB pager. (CVE-2023-4693)

Topics Covered

security advisory Ubuntu heap overflow out-of-bounds read GRUB2

Update Instructions

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 23.04:
   grub-efi-amd64                  2.06-2ubuntu17.2
   grub-efi-amd64-bin              2.06-2ubuntu17.220:32
   grub-efi-amd64-signed           1.193.2+2.06-2ubuntu17.2
   grub-efi-arm64                  2.06-2ubuntu17.2
   grub-efi-arm64-bin              2.06-2ubuntu17.2
   grub-efi-arm64-signed           1.193.2+2.06-2ubuntu17.2

Ubuntu 22.04 LTS:
   grub-efi-amd64                  2.06-2ubuntu14.4
   grub-efi-amd64-bin              2.06-2ubuntu14.4
   grub-efi-amd64-signed           1.187.6+2.06-2ubuntu14.4
   grub-efi-arm64                  2.06-2ubuntu14.4
   grub-efi-arm64-bin              2.06-2ubuntu14.4
   grub-efi-arm64-signed           1.187.6+2.06-2ubuntu14.4

Ubuntu 20.04 LTS:
   grub-efi-amd64-signed           1.187.6~20.04.1+2.06-2ubuntu14.4
   grub-efi-arm64-signed           1.187.6~20.04.1+2.06-2ubuntu14.4

In general, a standard system update will make all the necessary changes.