Vulnerability-Lookup

GHSA-7C38-49CX-FJVW

Vulnerability from github – Published: 2026-08-29 00:31 – Updated: 2026-08-29 00:31

Details

IGEL OS 12 before 12.9.0, 12.8.3 LTS and IGEL OS 11 before 11.11.150 contain a secure boot bypass vulnerability in the GRUB boot stage that allows physically present attackers to gain unauthorized root access by placing an unsigned empty file named igel.conf on a partition. Attackers can exploit GRUB's fail-open signature verification behavior to drop into an interactive GRUB prompt, then boot the device's own kernel with additional command-line arguments to obtain a root shell with the disk unlocked while leaving TPM PCR values unaltered.

Severity

6.1 (Medium)


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

6.8 (Medium)


                  
                    CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

Show details on source website

JSON

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{
  "affected": [],
  "aliases": [
    "CVE-2026-82018"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-636"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-28T22:16:55Z",
    "severity": "MODERATE"
  },
  "details": "IGEL OS 12 before 12.9.0, 12.8.3 LTS and IGEL OS 11 before 11.11.150 contain a secure boot bypass vulnerability in the GRUB boot stage that allows physically present attackers to gain unauthorized root access by placing an unsigned empty file named igel.conf on a partition. Attackers can exploit GRUB\u0027s fail-open signature verification behavior to drop into an interactive GRUB prompt, then boot the device\u0027s own kernel with additional command-line arguments to obtain a root shell with the disk unlocked while leaving TPM PCR values unaltered.",
  "id": "GHSA-7c38-49cx-fjvw",
  "modified": "2026-08-29T00:31:03Z",
  "published": "2026-08-29T00:31:03Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-82018"
    },
    {
      "type": "WEB",
      "url": "https://blog.amberwolf.com/blog/2026/august/thin-client-thin-crypto-overview"
    },
    {
      "type": "WEB",
      "url": "https://kb.igel.com/en/security-safety/current/isn-2026-20-grub-shell-escape-in-igel-os"
    },
    {
      "type": "WEB",
      "url": "https://media.defcon.org/DEF%20CON%2034/DEF%20CON%2034%20presentations/DEF%20CON%2034%20presentations/DEF%20CON%2034%20-%20Darren%20McDonald%20-%20Thin%20Client%20Thin%20Crypto%20-%20Bypassing%20Full-Desk%20Encryption%20Across%20Three%20Major%20Thin%20Clients%20Vendors%20without%20Breaking%20a%20Ci.pdf"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/igel-os-12-11-secure-boot-bypass-via-unsigned-igel-conf-file"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
      "type": "CVSS_V4"
    }
  ]
}

CVE-2026-82018 (GCVE-0-2026-82018)

Vulnerability from cvelistv5 – Published: 2026-08-28 21:11 – Updated: 2026-08-28 21:11

Title

IGEL OS 12 / 11 Secure Boot Bypass via Unsigned igel.conf File

Summary

Severity

6.8 (Medium)


                        
                          CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

6.1 (Medium)


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

CWE

CWE-636 - Not Failing Securely ('Failing Open')

Assigner

VulnCheck mitre root

References

4 references

URL	Tags
https://kb.igel.com/en/security-safety/current/is…	vendor-advisorypatch
https://blog.amberwolf.com/blog/2026/august/thin-…	technical-description
https://media.defcon.org/DEF%20CON%2034/DEF%20CON…
https://www.vulncheck.com/advisories/igel-os-12-1…	third-party-advisory

Impacted products

2 products

Vendor	Product	Version
IGEL	IGEL OS 12	Affected: 12.0.0 , ≤ 12.8.2 (semver) Unaffected: 12.8.3 (semver) Unaffected: 12.9.0 (semver)
IGEL	IGEL OS 11	Affected: 11.0.0 , < 11.11.150 (semver)

Date Public

2026-06-17 00:00

Credits

Darren McDonald from AmberWolf

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "affected",
          "product": "IGEL OS 12",
          "vendor": "IGEL",
          "versions": [
            {
              "lessThanOrEqual": "12.8.2",
              "status": "affected",
              "version": "12.0.0",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "12.8.3",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "12.9.0",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "IGEL OS 11",
          "vendor": "IGEL",
          "versions": [
            {
              "lessThan": "11.11.150",
              "status": "affected",
              "version": "11.0.0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Darren McDonald from AmberWolf"
        }
      ],
      "datePublic": "2026-06-17T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "IGEL OS 12 before 12.9.0, 12.8.3 LTS and IGEL OS 11 before 11.11.150 contain a secure boot bypass vulnerability in the GRUB boot stage that allows physically present attackers to gain unauthorized root access by placing an unsigned empty file named igel.conf on a partition. Attackers can exploit GRUB\u0027s fail-open signature verification behavior to drop into an interactive GRUB prompt, then boot the device\u0027s own kernel with additional command-line arguments to obtain a root shell with the disk unlocked while leaving TPM PCR values unaltered."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "PHYSICAL",
            "baseScore": 6.8,
            "baseSeverity": "MEDIUM",
            "exploitMaturity": "NOT_DEFINED",
            "privilegesRequired": "NONE",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        },
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "PHYSICAL",
            "availabilityImpact": "NONE",
            "baseScore": 6.1,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
            "version": "3.1"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-636",
              "description": "Not Failing Securely (\u0027Failing Open\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-28T21:11:43.223Z",
        "orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
        "shortName": "VulnCheck"
      },
      "references": [
        {
          "name": "Vendor Advisory",
          "tags": [
            "vendor-advisory",
            "patch"
          ],
          "url": "https://kb.igel.com/en/security-safety/current/isn-2026-20-grub-shell-escape-in-igel-os"
        },
        {
          "name": "AmberWolf Blog",
          "tags": [
            "technical-description"
          ],
          "url": "https://blog.amberwolf.com/blog/2026/august/thin-client-thin-crypto-overview/"
        },
        {
          "name": "DEF CON 34 Presentation",
          "url": "https://media.defcon.org/DEF%20CON%2034/DEF%20CON%2034%20presentations/DEF%20CON%2034%20presentations/DEF%20CON%2034%20-%20Darren%20McDonald%20-%20Thin%20Client%20Thin%20Crypto%20-%20Bypassing%20Full-Desk%20Encryption%20Across%20Three%20Major%20Thin%20Clients%20Vendors%20without%20Breaking%20a%20Ci.pdf"
        },
        {
          "tags": [
            "third-party-advisory"
          ],
          "url": "https://www.vulncheck.com/advisories/igel-os-12-11-secure-boot-bypass-via-unsigned-igel-conf-file"
        }
      ],
      "source": {
        "discovery": "EXTERNAL"
      },
      "title": "IGEL OS 12 / 11 Secure Boot Bypass via Unsigned igel.conf File",
      "x_generator": {
        "engine": "vulncheck"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
    "assignerShortName": "VulnCheck",
    "cveId": "CVE-2026-82018",
    "datePublished": "2026-08-28T21:11:24.911Z",
    "dateReserved": "2026-08-27T21:39:20.459Z",
    "dateUpdated": "2026-08-28T21:11:43.223Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
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.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.

Action not permitted

GHSA-7C38-49CX-FJVW

CVE-2026-82018 (GCVE-0-2026-82018)

Tags

Sightings

Nomenclature