Protect yourself against future threats.
=========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2024.2398 shim bug fix update 19 April 2024 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- 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-2024:1876 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 - --------------------------BEGIN INCLUDED TEXT-------------------- ===================================================================== Red Hat Security Advisory Synopsis: Important: shim bug fix update Advisory ID: RHSA-2024:1876 Product: Red Hat Enterprise Linux BaseOS EUS (v.9.2) Advisory URL: https://access.redhat.com/errata/RHSA-2024:1876 Issue date: 2024-04-18 CVE Names: CVE-2023-40546 CVE-2023-40547 CVE-2023-40548 CVE-2023-40549 CVE-2023-40550 CVE-2023-40551 ===================================================================== 1. Summary: An update for shim is now available for Red Hat Enterprise Linux 9.2 Extended Update Support. 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 EUS (v.9.2) - aarch64, 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 EUS (v.9.2) Source: shim-0:15.8-3.el9_2.src.rpm aarch64: shim-aa64-0:15.8-3.el9_2.aarch64.rpm x86_64: shim-x64-0:15.8-3.el9_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 - --------------------------END INCLUDED TEXT---------------------- You have received this e-mail bulletin as a result of your organisation's registration with AusCERT. The mailing list you are subscribed to is maintained within your organisation, so if you do not wish to continue receiving these bulletins you should contact your local IT manager. If you do not know who that is, please send an email to auscert@auscert.org.au and we will forward your request to the appropriate person. NOTE: Third Party Rights This security bulletin is provided as a service to AusCERT's members. As AusCERT did not write the document quoted above, AusCERT has had no control over its content. The decision to follow or act on information or advice contained in this security bulletin is the responsibility of each user or organisation, and should be considered in accordance with your organisation's site policies and procedures. AusCERT takes no responsibility for consequences which may arise from following or acting on information or advice contained in this security bulletin. NOTE: This is only the original release of the security bulletin. It may not be updated when updates to the original are made. If downloading at a later date, it is recommended that the bulletin is retrieved directly from the author's website to ensure that the information is still current. Contact information for the authors of the original document is included in the Security Bulletin above. If you have any questions or need further information, please contact them directly. Previous advisories and external security bulletins can be retrieved from: https://www.auscert.org.au/bulletins/ =========================================================================== Australian Computer Emergency Response Team The University of Queensland Brisbane Qld 4072 Internet Email: auscert@auscert.org.au Facsimile: (07) 3365 7031 Telephone: (07) 3365 4417 (International: +61 7 3365 4417) AusCERT personnel answer during Queensland business hours which are GMT+10:00 (AEST). On call after hours for member emergencies only. ===========================================================================