CVE-2023-40549
Published: 23 January 2024
An out-of-bounds read flaw was found in Shim due to the lack of proper boundary verification during the load of a PE binary. This flaw allows an attacker to load a crafted PE binary, triggering the issue and crashing Shim, resulting in a denial of service.
Notes
| Author | Note |
|---|---|
| eslerm | UEFI Security Response Team states that dbx update is not needed secureboot-db should only ever be updated after shim secureboot-db is not updated on ESM releases as doing so would revoke install media keys Note that key revocation is required to protect against evil housekeeper attacks (such as BlackLotus) |
Priority
Status
| Package | Release | Status |
|---|---|---|
|
secureboot-db Launchpad, Ubuntu, Debian |
bionic |
Not vulnerable
(sbat only update)
|
| focal |
Not vulnerable
(sbat only update)
|
|
| jammy |
Not vulnerable
(sbat only update)
|
|
| lunar |
Ignored
(end of life, was needs-triage)
|
|
| mantic |
Not vulnerable
(sbat only update)
|
|
| noble |
Not vulnerable
(sbat only update)
|
|
| trusty |
Not vulnerable
(sbat only update)
|
|
| upstream |
Not vulnerable
(sbat only update)
|
|
| xenial |
Not vulnerable
(sbat only update)
|
|
|
shim Launchpad, Ubuntu, Debian |
bionic |
Needs triage
|
| focal |
Needed
|
|
| jammy |
Needed
|
|
| lunar |
Ignored
(end of life, was needs-triage)
|
|
| mantic |
Needed
|
|
| noble |
Released
(15.8-0ubuntu1)
|
|
| trusty |
Ignored
(install media keys will never be revoked)
|
|
| upstream |
Needs triage
|
|
| xenial |
Ignored
(install media keys will never be revoked)
|
|
|
Patches: upstream: https://github.com/rhboot/shim/commit/afdc5039de0a4a3a40162a32daa070f94a883f09 |
||
|
shim-signed Launchpad, Ubuntu, Debian |
bionic |
Needs triage
|
| focal |
Needed
|
|
| jammy |
Needed
|
|
| lunar |
Ignored
(end of life, was needs-triage)
|
|
| mantic |
Needed
|
|
| noble |
Released
(15.8)
|
|
| trusty |
Ignored
(install media keys will never be revoked)
|
|
| upstream |
Needs triage
|
|
| xenial |
Ignored
(install media keys will never be revoked)
|
|
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 5.5 |
| Attack vector | Local |
| Attack complexity | Low |
| Privileges required | Low |
| User interaction | None |
| Scope | Unchanged |
| Confidentiality | None |
| Integrity impact | None |
| Availability impact | High |
| Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |