CVE-2023-40548 — Out-of-bounds Write in Redhat Shim

CWE-787 — Out-of-bounds WriteCWE-190 — Integer Overflow or WraparoundCWE-122 — Heap-based Buffer Overflow7 documents7 sources
Severity
7.4HIGHNVD
EPSS
0.0%
top 90.78%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
2
Redhat ShimFedoraproject Fedora
Timeline
PublishedJan 29

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.

CVSS vector

CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:HExploitability: 1.4 | Impact: 5.9

Affected Packages2 packages

▶NVDredhat/shim< 15.8+1
▶Debianredhat/shim< 15.8-1~deb11u1+3

Also affects: Fedora 39

🔴Vulnerability Details

3
OSV
CVE-2023-40548: A buffer overflow was found in Shim in the 32-bit system↗2024-01-29
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CVEList
Shim: interger overflow leads to heap buffer overflow in verify_sbat_section on 32-bits systems↗2024-01-29
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GHSA
GHSA-7cf2-63mg-hv4j: A buffer overflow was found in Shim in the 32-bit system↗2024-01-29
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📋Vendor Advisories

3
Microsoft
Shim: interger overflow leads to heap buffer overflow in verify_sbat_section on 32-bits systems↗2024-01-09
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Red Hat
shim: Interger overflow leads to heap buffer overflow in verify_sbat_section on 32-bits systems↗2023-10-03
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Debian
CVE-2023-40548: shim - A buffer overflow was found in Shim in the 32-bit system. The overflow happens d...↗2023
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