CVE-2022-28737

Publication date 20 July 2023

Last updated 18 August 2025

Ubuntu priority

Cvss 3 Severity Score

Description

There’s a possible overflow in handle_image() when shim tries to load and execute crafted EFI executables; The handle_image() function takes into account the SizeOfRawData field from each section to be loaded. An attacker can leverage this to perform out-of-bound writes into memory. Arbitrary code execution is not discarded in such scenario.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
shim	25.10 questing	Not affected
	25.04 plucky	Not affected
	24.10 oracular	Not affected
	24.04 LTS noble	Not affected
	23.10 mantic	Not affected
	23.04 lunar	Not affected
	22.10 kinetic	Ignored end of life, was needed
	22.04 LTS jammy	Fixed 15.7-0ubuntu1
	21.10 impish	Ignored end of life
	20.04 LTS focal	Fixed 15.7-0ubuntu1
	18.04 LTS bionic	Vulnerable, work in progress
	16.04 LTS xenial	Ignored install media keys will never be revoked
	14.04 LTS trusty	Ignored install media keys will never be revoked

Notes

mdeslaur

This is fixed in 15.7-0ubuntu1 that is currently in the -updates pocket of focal, jammy, and kinetic.

eslerm

keys not updated on ESM releases as doing so would revoke install media keys

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
shim	Upstream: e99bdbb Upstream: 159151b

Severity score breakdown

Parameter	Value
Base score	6.5 · Medium
Attack vector	Local
Attack complexity	Low
Privileges required	High
User interaction	Required
Scope	Unchanged
Confidentiality	High
Integrity impact	High
Availability impact	High
Vector	CVSS:3.1/AV:L/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:H

References

Related Ubuntu Security Notices (USN)

USN-6355-1
GRUB2 vulnerabilities
8 September 2023