SARA / Free Tools / CVE / CVE-2023-40551

CVE-2023-40551 — A flaw was found in the MZ binary format in Shim

A flaw was found in the MZ binary format in Shim. An out-of-bounds read may occur, leading to a crash or possible exposure of sensitive data during the system's boot phase.

CVSS
5.1 MEDIUM
EPSS
1.00% (top 97.00%)
CWE
CWE-125
Published
2024-01-29T16:46:43.579Z
Last modified
2025-11-20T19:53:39.583Z
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:H

01What is this vulnerability?

A flaw was found in the MZ binary format in Shim. An out-of-bounds read may occur, leading to a crash or possible exposure of sensitive data during the system's boot phase.

02Affected products

VendorProductVersions
Red HatRed Hat Enterprise Linux 70:15.8-3.el7
Red HatRed Hat Enterprise Linux 70:15.8-1.el7
Red HatRed Hat Enterprise Linux 80:15.8-4.el8_9
Red HatRed Hat Enterprise Linux 8.2 Advanced Update Support0:15.8-2.el8_2
Red HatRed Hat Enterprise Linux 8.2 Telecommunications Update Service0:15.8-2.el8_2
Red HatRed Hat Enterprise Linux 8.2 Update Services for SAP Solutions0:15.8-2.el8_2
Red HatRed Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support0:15.8-2.el8_4
Red HatRed Hat Enterprise Linux 8.4 Telecommunications Update Service0:15.8-2.el8_4
Red HatRed Hat Enterprise Linux 8.4 Update Services for SAP Solutions0:15.8-2.el8_4
Red HatRed Hat Enterprise Linux 8.6 Extended Update Support0:15.8-2.el8_6
Red HatRed Hat Enterprise Linux 8.8 Extended Update Support0:15.8-2.el8
Red HatRed Hat Enterprise Linux 8.8 Extended Update Support0:15.8-2.el8
Red HatRed Hat Enterprise Linux 90:15.8-4.el9_3
Red HatRed Hat Enterprise Linux 9.0 Extended Update Support0:15.8-3.el9
Red HatRed Hat Enterprise Linux 9.0 Extended Update Support0:15.8-2.el9
Red HatRed Hat Enterprise Linux 9.0 Extended Update Support0:15.8-2.el9
Red HatRed Hat Enterprise Linux 9.2 Extended Update Support0:15.8-3.el9_2

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Open the Sigma generator with a pre-filled prompt for this CVE to draft a starting detection in your stack of choice:

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07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

09References

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