CVE-2023-40547
Shim: rce in http boot support may lead to secure boot bypass
02 Description
Shim: rce in http boot support may lead to secure boot bypass
03 Exploitation and scoring
- Exploitation
- Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
- SSVC decision
- ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
- AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
- Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.
- EPSS probability
- 5.41% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 92.6% of scored records. A rank, not a probability.
- NVD base score
- 8.3 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
- NVD analysis status
- Modified. NVD last modified this record on 2026-06-26.
- Red Hat severity
- Important. Red Hat's rating for its own products, not a CVSS rating.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2024-01-25 15:54Z2 YR AGO
- Last updated
- 2026-06-26 09:43Z4 MO AGO
- Reserved
- 2023-08-15
- Assigning CNA
- redhat
- Record state
- PUBLISHED
- Severity
- High (CVSS 8.3)
- CNA CVSS vector
- CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
- Weaknesses
- Data version
- 5.2
- Document digest
- bf90c6ab7b9e70868bfcd5eca182d62880679014348fc7bb769b96ca14e4d465
05 Affected products
06 References
- access.redhat.comRHSA-2024:1834https://access.redhat.com/errata/RHSA-2024:1834
- access.redhat.comRHSA-2024:1835https://access.redhat.com/errata/RHSA-2024:1835
- access.redhat.comRHSA-2024:1873https://access.redhat.com/errata/RHSA-2024:1873
- access.redhat.comRHSA-2024:1876https://access.redhat.com/errata/RHSA-2024:1876
- access.redhat.comRHSA-2024:1883https://access.redhat.com/errata/RHSA-2024:1883
- access.redhat.comRHSA-2024:1902https://access.redhat.com/errata/RHSA-2024:1902
- access.redhat.comRHSA-2024:1903https://access.redhat.com/errata/RHSA-2024:1903
- access.redhat.comRHSA-2024:1959https://access.redhat.com/errata/RHSA-2024:1959
- access.redhat.comRHSA-2024:2086https://access.redhat.com/errata/RHSA-2024:2086
- access.redhat.comhttps://access.redhat.com/security/cve/CVE-2023-40547
- bugzilla.redhat.comRHBZ#2234589https://bugzilla.redhat.com/show_bug.cgi?id=2234589
- www.openwall.comhttp://www.openwall.com/lists/oss-security/2024/01/26/1
- lists.debian.orghttps://lists.debian.org/debian-lts-announce/2024/05/msg00009.html
07 Fixed in
AlmaLinux 8
- shim-aa64 Fixed in 15.8-4.el8_9.alma.1
- shim-ia32 Fixed in 15.8-4.el8_9.alma.1
- shim-x64 Fixed in 15.8-4.el8_9.alma.1
Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
AlmaLinux 9
- shim-aa64 Fixed in 15.8-4.el9_3.alma.1
- shim-x64 Fixed in 15.8-4.el9_3.alma.1
Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
CloudLinux 8
- shim-aa64 Fixed in 15.8-4.el8_9.alma.1
- shim-ia32 Fixed in 15.8-4.el8_9.alma.1
- shim-x64 Fixed in 15.8-4.el8_9.alma.1
Derived from AlmaLinux 8. Partial coverage: only packages taken from AlmaLinux 8 are listed.
Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
CloudLinux 9
- shim-aa64 Fixed in 15.8-4.el9_3.alma.1
- shim-x64 Fixed in 15.8-4.el9_3.alma.1
Derived from AlmaLinux 9. Partial coverage: only packages taken from AlmaLinux 9 are listed.
Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
Debian 12
- shim Fixed in 15.8-1~deb12u1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 13
- shim Fixed in 15.8-1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 14
- shim Fixed in 15.8-1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 14.04 LTS
- shim No fix yet
- shim-signed No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 16.04 LTS
- shim No fix yet
- shim-signed No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 18.04 LTS
- shim No fix yet
- shim-signed No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 20.04 LTS
- shim Fixed in 15.8-0ubuntu1
- shim-signed Fixed in 1.40.10
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 22.04 LTS
- shim Fixed in 15.8-0ubuntu1
- shim-signed Fixed in 1.51.4
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 24.04 LTS
- shim Fixed in 15.8-0ubuntu1
- shim-signed Fixed in 1.58
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.