Vulnerability-Lookup

GHSA-4JVR-VJ2C-8Q37

Vulnerability from github – Published: 2026-02-04 23:12 – Updated: 2026-02-04 23:12

Summary

EVE Seals Vault Key With SHA1 PCRs

Details

Impact

The vault key is sealed using SHA1 PCRs instead of SHA256 PCRs

Thus an attacker with physical access to an EVE-OS device can try to brute force creating a kernel or rootfs image which produces the same SHA1 PCR but with malicious content.

Patches

Fixed in 9.4.3-lts and 10.1.0

Workarounds

None

Severity

6.7 (Medium)


                  
                    CVSS:3.1/AV:P/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/lf-edge/eve"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.0.0-20230519072751-977f42b07fa9"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2023-43635"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-327",
      "CWE-328",
      "CWE-522"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-02-04T23:12:29Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "### Impact\n\nThe vault key is sealed using SHA1 PCRs instead of SHA256 PCRs\n\nThus an attacker with physical access to an EVE-OS device can try to brute force creating a kernel or rootfs image which produces the same SHA1 PCR but with malicious content.\n\n### Patches\n\nFixed in 9.4.3-lts and 10.1.0\n\n### Workarounds\n\nNone",
  "id": "GHSA-4jvr-vj2c-8q37",
  "modified": "2026-02-04T23:12:29Z",
  "published": "2026-02-04T23:12:29Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/lf-edge/eve/security/advisories/GHSA-4jvr-vj2c-8q37"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-43635"
    },
    {
      "type": "WEB",
      "url": "https://asrg.io/security-advisories/cve-2023-43635"
    },
    {
      "type": "WEB",
      "url": "https://asrg.io/security-advisories/vault-key-sealed-with-sha1-pcrs"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/lf-edge/eve"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:P/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "EVE Seals Vault Key With SHA1 PCRs"
}

CVE-2023-43635 (GCVE-0-2023-43635)

Vulnerability from cvelistv5 – Published: 2023-09-20 14:58 – Updated: 2024-09-25 14:37

Title

Vault Key Sealed With SHA1 PCRs

Summary

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 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.

Severity

8.8 (High)


                        
                          CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

SSVC

Exploitation: none Automatable: no Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2024-09-25 14:32 UTC

CWE

CWE-522 - Insufficiently Protected Credentials
CWE-328 - Use of Weak Hash

Assigner

ASRG CNA under the icscert root

CNA scorecard – unranked: 8 records in the last 180 days, 10 needed details

References

1 reference

URL	Tags
https://asrg.io/security-advisories/cve-2023-43635/

Impacted products

2 products

Vendor	Product	Version
LF-Edge, Zededa	EVE OS	Affected: 0 , < 9.5.0 (release)
linuxfoundation	edge_virtualization_engine	Affected: 0 , < 9.5.0 (custom) cpe:2.3:o:linuxfoundation:edge_virtualization_engine::::::::

Date Public

2023-09-20 14:57

Credits

Ilay Levi

Show details on NVD website

JSON

To clipboard

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Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
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Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
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Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

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