CVE-2023-43635
Crypto Weakness in Linuxfoundation Edge Virtualization Engine ≤ 9.5.0
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:HSummary
CVE-2023-43635 is a high-severity Use of Weak Hash (CWE-328) vulnerability in Linuxfoundation Edge Virtualization Engine. Its CVSS base score is 8.8 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Unsecured Credentials (T1552); ranked at the 1th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2023-48035
Vulnerability Data
Vault Key Sealed With SHA1 PCRs The measured boot solution implemented in EVE OS leans on a PCR locking mechanism. Different parts of the system update different PCR values in the TPM, resulting in a unique value for each PCR…
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entry. These PCRs are then used in order to seal/unseal a key from the TPM which is used to encrypt/decrypt the “vault” directory. This “vault” directory is the most sensitive point in the system and as such, its content should be protected. This mechanism is noted in Zededa’s documentation as the “measured boot” mechanism, designed to protect said “vault”. The code that’s responsible for generating and fetching the key from the TPM assumes that SHA256 PCRs are used in order to seal/unseal the key, and as such their presence is being checked. The issue here is that the key is not sealed using SHA256 PCRs, but using SHA1 PCRs. This leads to several issues: • Machines that have their SHA256 PCRs enabled but SHA1 PCRs disabled, as well as not sealing their keys at all, meaning the “vault” is not protected from an attacker. • SHA1 is considered insecure and reduces the complexity level required to unseal the key in machines which have their SHA1 PCRs enabled. An attacker can very easily retrieve the contents of the “vault”, which will effectively render the “measured boot” mechanism meaningless.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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- 12 hardening rules · 7 OS baselines
V11.2.3V6.5.2V11.3.3
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.
Enforces approved cryptographic algorithms for each use case, blocking use of broken or risky algorithms.
Flaw remediation replaces broken or risky cryptographic algorithms once safer implementations are released by vendors.
Training instructs users on protecting credentials from disclosure or unauthorized access.
Training records for security awareness and role-based training verify education on credential protection practices, tangibly reducing risks from mishandling or exposing credentials.
Contacts with security groups provide timely information on broken or risky cryptographic algorithms, reducing the likelihood of their selection and use.
Protecting authenticator content from unauthorized disclosure and modification while requiring protective controls addresses insufficiently protected credentials.
Rules of behavior include credential protection and non-sharing requirements, reducing exposure of insufficiently protected credentials.
Ongoing education and sharing of recommended practices helps organizations identify and migrate away from broken or risky cryptographic algorithms.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Encrypting data-at-rest fully prevents insecure credential storage while only partially satisfying the broader data-protection outcome.
Encrypting data-in-transit fully prevents interception of credentials in motion while only partially satisfying the broader data-protection outcome.
Secure-SDLC requirements explicitly forbid weak cryptographic algorithms, fully preventing CWE-328 while covering only one aspect of development practice.
Credential management practices directly reduce insecure storage/transmission but do not guarantee encryption or transport protection.
Protecting identity assertions covers conveyance of credentials but is narrower than full credential lifecycle protection.
Authentication policies can enforce stronger credential handling yet address only verification, not storage or transit protection.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Requiring protected storage, transmission, and non-display of passwords prevents credentials from being stored or sent in clear text where they can be harvested by unauthorized actors.
Mandates use of approved cryptographic algorithms, directly preventing weak-hash selection.
Security testing can detect weak-hash usage but does not prescribe algorithm choice.
Forbidding clear-text transmission and display of passwords, plus the use of stronger alternatives to passwords, prevents credentials from being obtained or reused by attackers.
Acceptable-use expectations that cover protection of credentials and information assets throughout their lifecycle discourage practices that expose or mishandle authentication material.
The explicit call-out of cryptography-related legal constraints (import/export, key escrow, digital-signature validity) reduces the likelihood that an organization will adopt broken or non-compliant cryptographic algorithms that violate those rules.
Hardening callouts derived
Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).
Oracle Linux 8 (1 rule)
- V-248524 OL 8 must implement NIST FIPS-validated cryptography for the following: To provision digital signatures, to generate cryptographic hashes, and to protect data requiring data-at-rest protections in accordance with applicable federal laws, Executive Orders, directives, policies, regulations, and standards. prevents CWE-327
Windows 10 (1 rule)
- V-220937 The system must be configured to prevent the storage of the LAN Manager hash of passwords. prevents CWE-327, CWE-328
Windows 11 (1 rule)
- V-253461 The system must be configured to prevent the storage of the LAN Manager hash of passwords. prevents CWE-327, CWE-328
Windows Server 2016 (1 rule)
- V-225053 Windows Server 2016 must be configured to prevent the storage of the LAN Manager hash of passwords. prevents CWE-327, CWE-328
Windows Server 2019 (1 rule)
- V-205654 Windows Server 2019 must be configured to prevent the storage of the LAN Manager hash of passwords. prevents CWE-327, CWE-328
Windows Server 2022 (1 rule)
- V-254474 Windows Server 2022 must be configured to prevent the storage of the LAN Manager hash of passwords. prevents CWE-327, CWE-328