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:HCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
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 OS Credential Dumping (T1003); ranked at the 2th 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…
more
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
—
—
- 3 hardening rules · 3 OS baselines
V11.2.3V6.5.2
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.
Proper data-at-rest integrity protection requires strong cryptographic hashes, directly blocking weak-hash usage.
Data-in-transit integrity likewise depends on strong hashes, so the control prevents the weakness while the weakness only partially satisfies the outcome.
Secure-SDLC requirements explicitly forbid weak cryptographic algorithms, fully preventing CWE-328 while covering only one aspect of development practice.
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.
A.5.10 only requires awareness, a topic-specific acceptable-use policy stating expected behaviours/monitoring, and procedures referencing other controls (e.g. access restrictions, marking, disposal); it performs none of the verb on CWE-522's insecure credential transmission/storage, which requires technical protections like encryption or secure channels that this governance clause does not supply.
A.5.17 mandates secure allocation, transmission, storage, hashing/encryption per 8.24, strong non-reusable passwords, immediate change of defaults/compromise, and no cleartext — directly stopping exploitation of insufficiently protected credentials with only a bounded remainder (e.g. non-password authenticators or post-storage exposure vectors outside its scope).
A.5.31 only requires identifying, reviewing and considering legal/regulatory/contractual requirements (including crypto restrictions); it does not itself stop use of a broken algorithm or block its exploitation
A.5.6 only promotes membership in groups to receive early warnings, advisories, and specialist advice about vulnerabilities (including risky crypto); it does not stop exploitation of an already-present broken algorithm, which requires other controls (e.g. A.8.24) to act.
A.6.2 sets contractual terms, NDAs, and communicates responsibilities to personnel; it has no technical effect on how credentials are protected in transmission or storage and cannot stop exploitation of CWE-522
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` (higher-evidence rows only; rows rated `none` are excluded).
Windows 10 (1 rule)
- V-220937 The system must be configured to prevent the storage of the LAN Manager hash of passwords. blocks 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. blocks 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. blocks CWE-328