Protect yourself against future threats.
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AUSCERT External Security Bulletin Redistribution
ESB-2024.2357
shim security update
17 April 2024
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AusCERT Security Bulletin Summary
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Product: shim
Publisher: Red Hat
Operating System: Red Hat
Resolution: Patch/Upgrade
CVE Names: CVE-2023-40546 CVE-2023-40547 CVE-2023-40548
CVE-2023-40549 CVE-2023-40550 CVE-2023-40551
Original Bulletin:
https://access.redhat.com/errata/RHSA-2024:1834
Comment: CVSS (Max): 8.3 CVE-2023-40547 (CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H)
CVSS Source: Red Hat
Calculator: https://www.first.org/cvss/calculator/3.1#CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
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Red Hat Security Advisory
Synopsis: Important: shim security update
Advisory ID: RHSA-2024:1834
Product: Red Hat Enterprise Linux BaseOS AUS (v. 8.2)
Advisory URL: https://access.redhat.com/errata/RHSA-2024:1834
Issue date: 2024-04-16
CVE Names: CVE-2023-40546 CVE-2023-40547 CVE-2023-40548 CVE-2023-40549
CVE-2023-40550 CVE-2023-40551
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1. Summary:
An update for shim is now available for Red Hat Enterprise Linux 8.2 Advanced
Update Support, Red Hat Enterprise Linux 8.2 Update Services for SAP Solutions,
and Red Hat Enterprise Linux 8.2 Telecommunications Update Service.
Red Hat Product Security has rated this update as having a security impact of
Important. A Common Vulnerability Scoring System (CVSS) base score, which gives
a detailed severity rating, is available for each vulnerability from the CVE
link(s) in the References section.
2. Relevant releases/architectures:
Red Hat Enterprise Linux BaseOS AUS (v. 8.2) - x86_64
Red Hat Enterprise Linux BaseOS E4S (v. 8.2) - x86_64
Red Hat Enterprise Linux BaseOS TUS (v. 8.2) - x86_64
3. Description:
The shim package contains a first-stage UEFI boot loader that handles chaining
to a trusted full boot loader under secure boot environments.
Security Fix(es):
* shim: RCE in http boot support may lead to Secure Boot bypass (CVE-2023-40547)
* shim: Interger overflow leads to heap buffer overflow in verify_sbat_section
on 32-bits systems (CVE-2023-40548)
* shim: Out-of-bounds read printing error messages (CVE-2023-40546)
* shim: Out-of-bounds read in verify_buffer_authenticode() malformed PE file
(CVE-2023-40549)
* shim: Out-of-bound read in verify_buffer_sbat() (CVE-2023-40550)
* shim: out of bounds read when parsing MZ binaries (CVE-2023-40551)
For more details about the security issue(s), including the impact, a CVSS
score, acknowledgments, and other related information, refer to the CVE page(s)
listed in the References section.
4. Solution:
For details on how to apply this update, which includes the changes described in
this advisory, refer to:
https://access.redhat.com/articles/11258
5. Bugs fixed (https://bugzilla.redhat.com/):
2241796 - CVE-2023-40546 - shim: Out-of-bounds read printing error messages
2234589 - CVE-2023-40547 - shim: RCE in http boot support may lead to Secure
Boot bypass
2241782 - CVE-2023-40548 - shim: Interger overflow leads to heap buffer overflow
in verify_sbat_section on 32-bits systems
2241797 - CVE-2023-40549 - shim: Out-of-bounds read in
verify_buffer_authenticode() malformed PE file
2259915 - CVE-2023-40550 - shim: Out-of-bound read in verify_buffer_sbat()
2259918 - CVE-2023-40551 - shim: out of bounds read when parsing MZ binaries
6. Package List:
Red Hat Enterprise Linux BaseOS AUS (v. 8.2)
Source:
shim-0:15.8-2.el8_2.src.rpm
x86_64:
shim-ia32-0:15.8-2.el8_2.x86_64.rpm
shim-x64-0:15.8-2.el8_2.x86_64.rpm
Red Hat Enterprise Linux BaseOS E4S (v. 8.2)
Source:
shim-0:15.8-2.el8_2.src.rpm
x86_64:
shim-ia32-0:15.8-2.el8_2.x86_64.rpm
shim-x64-0:15.8-2.el8_2.x86_64.rpm
Red Hat Enterprise Linux BaseOS TUS (v. 8.2)
Source:
shim-0:15.8-2.el8_2.src.rpm
x86_64:
shim-ia32-0:15.8-2.el8_2.x86_64.rpm
shim-x64-0:15.8-2.el8_2.x86_64.rpm
7. References:
https://access.redhat.com/security/cve/CVE-2023-40546
https://access.redhat.com/security/cve/CVE-2023-40547
https://access.redhat.com/security/cve/CVE-2023-40548
https://access.redhat.com/security/cve/CVE-2023-40549
https://access.redhat.com/security/cve/CVE-2023-40550
https://access.redhat.com/security/cve/CVE-2023-40551
https://access.redhat.com/security/updates/classification/#important
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