Vulnerability-Lookup

FKIE_CVE-2021-40818

Vulnerability from fkie_nvd - Published: 2021-09-08 22:15 - Updated: 2026-06-17 04:07

Severity

9.8 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Summary

scheme/webauthn.c in Glewlwyd SSO server through 2.5.3 has a buffer overflow during FIDO2 signature validation in webauthn registration.

References

URL	Tags
cve@mitre.org	https://bugs.debian.org/993867	Issue Tracking, Mailing List, Third Party Advisory
cve@mitre.org	https://github.com/babelouest/glewlwyd/commit/0efd112bb62f566877750ad62ee828bff579b4e2	Patch, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108	https://bugs.debian.org/993867	Issue Tracking, Mailing List, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108	https://github.com/babelouest/glewlwyd/commit/0efd112bb62f566877750ad62ee828bff579b4e2	Patch, Third Party Advisory

Impacted products

	Vendor	Product	Version
	glewlwyd_sso_server_project	glewlwyd_sso_server	*

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "n/a",
          "vendor": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "n/a"
            }
          ]
        }
      ],
      "source": "cve@mitre.org"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:glewlwyd_sso_server_project:glewlwyd_sso_server:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "CDD0EFAB-3548-4CC4-9D2E-DA747C67BB39",
              "versionEndIncluding": "2.5.3",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "scheme/webauthn.c in Glewlwyd SSO server through 2.5.3 has a buffer overflow during FIDO2 signature validation in webauthn registration."
    },
    {
      "lang": "es",
      "value": "El archivo scheme/webauthn.c en el servidor SSO de Glewlwyd versiones hasta 2.5.3, presenta un desbordamiento de b\u00fafer durante la comprobaci\u00f3n de la firma FIDO2 en el registro de webauthn"
    }
  ],
  "id": "CVE-2021-40818",
  "lastModified": "2026-06-17T04:07:28.683",
  "metrics": {
    "cvssMetricV2": [
      {
        "acInsufInfo": false,
        "baseSeverity": "HIGH",
        "cvssData": {
          "accessComplexity": "LOW",
          "accessVector": "NETWORK",
          "authentication": "NONE",
          "availabilityImpact": "PARTIAL",
          "baseScore": 7.5,
          "confidentialityImpact": "PARTIAL",
          "integrityImpact": "PARTIAL",
          "vectorString": "AV:N/AC:L/Au:N/C:P/I:P/A:P",
          "version": "2.0"
        },
        "exploitabilityScore": 10.0,
        "impactScore": 6.4,
        "obtainAllPrivilege": false,
        "obtainOtherPrivilege": false,
        "obtainUserPrivilege": false,
        "source": "nvd@nist.gov",
        "type": "Primary",
        "userInteractionRequired": false
      }
    ],
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 9.8,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.9,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ]
  },
  "published": "2021-09-08T22:15:11.383",
  "references": [
    {
      "source": "cve@mitre.org",
      "tags": [
        "Issue Tracking",
        "Mailing List",
        "Third Party Advisory"
      ],
      "url": "https://bugs.debian.org/993867"
    },
    {
      "source": "cve@mitre.org",
      "tags": [
        "Patch",
        "Third Party Advisory"
      ],
      "url": "https://github.com/babelouest/glewlwyd/commit/0efd112bb62f566877750ad62ee828bff579b4e2"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Issue Tracking",
        "Mailing List",
        "Third Party Advisory"
      ],
      "url": "https://bugs.debian.org/993867"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Patch",
        "Third Party Advisory"
      ],
      "url": "https://github.com/babelouest/glewlwyd/commit/0efd112bb62f566877750ad62ee828bff579b4e2"
    }
  ],
  "sourceIdentifier": "cve@mitre.org",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-120"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}

CVE-2021-40818 (GCVE-0-2021-40818)

Vulnerability from cvelistv5 – Published: 2021-09-08 21:47 – Updated: 2024-08-04 02:51

Summary

scheme/webauthn.c in Glewlwyd SSO server through 2.5.3 has a buffer overflow during FIDO2 signature validation in webauthn registration.

Severity

No CVSS data available.

CWE

Assigner

mitre mitre root

References

2 references

URL	Tags
https://github.com/babelouest/glewlwyd/commit/0ef…	x_refsource_MISC
https://bugs.debian.org/993867	x_refsource_MISC

Show details on NVD website

JSON

To clipboard

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      {
        "providerMetadata": {
          "dateUpdated": "2024-08-04T02:51:07.044Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
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        "references": [
          {
            "tags": [
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              "x_transferred"
            ],
            "url": "https://github.com/babelouest/glewlwyd/commit/0efd112bb62f566877750ad62ee828bff579b4e2"
          },
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            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://bugs.debian.org/993867"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
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          "vendor": "n/a",
          "versions": [
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      ],
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          "value": "scheme/webauthn.c in Glewlwyd SSO server through 2.5.3 has a buffer overflow during FIDO2 signature validation in webauthn registration."
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      ],
      "providerMetadata": {
        "dateUpdated": "2021-09-08T21:47:32.000Z",
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      },
      "references": [
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            "x_refsource_MISC"
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        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://bugs.debian.org/993867"
        }
      ],
      "x_legacyV4Record": {
        "CVE_data_meta": {
          "ASSIGNER": "cve@mitre.org",
          "ID": "CVE-2021-40818",
          "STATE": "PUBLIC"
        },
        "affects": {
          "vendor": {
            "vendor_data": [
              {
                "product": {
                  "product_data": [
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                      "version": {
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  "cveMetadata": {
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    "dateReserved": "2021-09-08T00:00:00.000Z",
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    "state": "PUBLISHED"
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  "dataType": "CVE_RECORD",
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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.
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.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.