CVE-2023-40548: shim Memory Corruption — Fix

Description

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.

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CVSS v3.1 Score

7.4

HIGH

CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Weakness Type (CWE)

CWE-787 Out-of-bounds Write

CWE-190 Integer Overflow

Affected Products

Vendor	Product	Versions
redhat	shim	< 15.8
redhat	shim	All
fedoraproject	fedora	All

References

Advisories & Patches

https://access.redhat.com/security/cve/CVE-2023-40548 https://bugzilla.redhat.com/show_bug.cgi?id=2241782 https://access.redhat.com/security/cve/CVE-2023-40548 https://bugzilla.redhat.com/show_bug.cgi?id=2241782

Other 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/errata/RHSA-2024:1834

Frequently Asked Questions

What is CVE-2023-40548? +

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. It has a CVSS v3.1 base score of 7.4 (HIGH).

How severe is CVE-2023-40548? +

CVE-2023-40548 has a CVSS v3.1 score of 7.4 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

What products are affected by CVE-2023-40548? +

CVE-2023-40548 affects products from fedoraproject, redhat, specifically: fedora, shim. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2023-40548? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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