What’s Vulnerable › Vulnerabilities
CVE-2023-40549: Shim: out-of-bounds read in verify_buffer_authenticode() malformed pe file
- Severity: medium (CVSS 5.5 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.4% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2024-01-29 · updated 2026-06-17
- Weakness: CWE-125
Description
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.
Affected products
- Fedoraproject Fedora: 39
- Red Hat Enterprise Linux: 8.0, 9.0
- Red Hat Bootloader Team shim: before 15.8 — fixed in 15.8
How to fix
Upgrade to a fixed version: Red Hat Bootloader Team shim 15.8. Check the vendor advisory for mitigations.
References
- https://access.redhat.com/errata/RHSA-2024:1834
- https://access.redhat.com/errata/RHSA-2024:1835
- 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-2024:1902
- https://access.redhat.com/errata/RHSA-2024:1903
- https://access.redhat.com/errata/RHSA-2024:1959
- https://access.redhat.com/errata/RHSA-2024:2086
- https://access.redhat.com/security/cve/CVE-2023-40549
- https://bugzilla.redhat.com/show_bug.cgi?id=2241797
- https://access.redhat.com/errata/RHSA-2024:1834
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