CVE-2023-40547
Published: 25 January 2024
Summary
CVE-2023-40547 is a high-severity Out-of-bounds Write (CWE-787) vulnerability in Redhat Enterprise Linux. Its CVSS base score is 8.3 (High).
Operationally, ranked in the top 11.1% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2023-45118
Vulnerability details
A remote code execution vulnerability was found in Shim. The Shim boot support trusts attacker-controlled values when parsing an HTTP response. This flaw allows an attacker to craft a specific malicious HTTP request, leading to a completely controlled out-of-bounds write…
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primitive and complete system compromise. This flaw is only exploitable during the early boot phase, an attacker needs to perform a Man-in-the-Middle or compromise the boot server to be able to exploit this vulnerability successfully.
- CWE(s)
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Requires unique identification of the service before communications, addressing failures to validate the origin of the interaction.
Trusted path establishment enforces validation that the communication originates from and reaches only the intended trusted system components.
Enforces validation of the true origin of DNS responses via signatures and chain-of-trust mechanisms.
Enforces origin validation of name/address data, eliminating reliance on unverified or impersonated DNS sources.
Mandates origin validation so that only legitimate endpoints can continue the authenticated session.
Out-of-bounds writes that corrupt control flow or inject shellcode are rendered non-executable by the same memory protections.