CVE-2023-40548: Shim: interger overflow leads to heap buffer overflow in verify_sbat_section on 32-bits systems
First published: Mon Oct 02 2023(Updated: )
A buffer overflow was found in Shim in the 32-bit system. The overflow happens due to an addition operation involving a user-controlled value parsed from the PE binary being used by Shim. This value is further used for memory allocation operations, leading to a heap-based buffer overflow. This flaw causes memory corruption and can lead to a crash or data integrity issues during the boot phase.
Credit: secalert@redhat.com
| Affected Software | Affected Version | How to fix |
|---|---|---|
| redhat/shim | <15.8 | 15.8 |
| Red Hat Shim | <15.8 | |
| Red Hat Shim | =15.8-rc1 | |
| Red Hat Fedora | =39 |
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Reference Links
- https://bugzilla.redhat.com/show_bug.cgi/show_bug.cgi?id=2259921
- https://access.redhat.com/errata/RHSA-2024:1834
- https://access.redhat.com/errata/RHSA-2024:1835
- https://bugzilla.redhat.com/show_bug.cgi/show_bug.cgi?id=2234589#c17
- https://access.redhat.com/errata/RHSA-2024:1873
- https://access.redhat.com/errata/RHSA-2024:1876
- https://access.redhat.com/errata/RHSA-2024:1883
- https://access.redhat.com/errata/RHSA-2024:1903
- https://access.redhat.com/errata/RHSA-2024:1902
- https://access.redhat.com/errata/RHSA-2024:1959
- https://access.redhat.com/errata/RHSA-2024:2086
- https://bugzilla.redhat.com/show_bug.cgi?id=2241782
- https://access.redhat.com/security/cve/CVE-2023-40548
- https://lists.debian.org/debian-lts-announce/2024/05/msg00009.html
Frequently Asked Questions
What is the severity of CVE-2023-40548?
CVE-2023-40548 is classified as a critical vulnerability due to the potential for a heap-based buffer overflow.
How do I fix CVE-2023-40548?
To mitigate CVE-2023-40548, you should upgrade to the latest version of Shim, specifically version 15.8 or higher.
What software is affected by CVE-2023-40548?
CVE-2023-40548 affects the Shim package in Red Hat and Fedora systems, specifically versions up to 15.8 and 39 respectively.
What risks does CVE-2023-40548 pose to my system?
Exploiting CVE-2023-40548 could allow an attacker to execute arbitrary code on the affected systems, compromising their integrity.
Is there a workaround for CVE-2023-40548?
Yes, temporarily restricting access to the affected Shim package can act as a workaround until a proper update is applied.
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