GCVE Workshop - 22 September 2026 (14:00-18:00), Luxembourg Before The Vulnopticon Conference - Registration

CVE-2021-3531 (GCVE-0-2021-3531)

Vulnerability from cvelistv5 – Published: 2021-05-18 00:00 – Updated: 2024-08-03 17:01
VLAI
Summary
A flaw was found in the Red Hat Ceph Storage RGW in versions before 14.2.21. When processing a GET Request for a swift URL that ends with two slashes it can cause the rgw to crash, resulting in a denial of service. The greatest threat to the system is of availability.
Severity
5.3 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
CWE
Assigner
References
Impacted products
Vendor Product Version CPE status
n/a ceph Affected: ceph 14.2.21
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-03T17:01:07.787Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "name": "[oss-security] 20210514 CVE-2021-3531: Ceph: RGW unauthenticated denial of service",
            "tags": [
              "mailing-list",
              "x_transferred"
            ],
            "url": "http://www.openwall.com/lists/oss-security/2021/05/14/5"
          },
          {
            "name": "[oss-security] 20210517 Re: CVE-2021-3531: Ceph: RGW unauthenticated denial of service",
            "tags": [
              "mailing-list",
              "x_transferred"
            ],
            "url": "http://www.openwall.com/lists/oss-security/2021/05/17/7"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1955326"
          },
          {
            "name": "FEDORA-2021-ec414c5e18",
            "tags": [
              "vendor-advisory",
              "x_transferred"
            ],
            "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LPCJN2YDZCBMF4FOJXSTAADKFGEQEO7O/"
          },
          {
            "name": "FEDORA-2021-6e540b85b9",
            "tags": [
              "vendor-advisory",
              "x_transferred"
            ],
            "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FX5ZHI5L7FOHXOSEV3TYBAL66DMLJ7V5/"
          },
          {
            "name": "FEDORA-2021-1bf13db941",
            "tags": [
              "vendor-advisory",
              "x_transferred"
            ],
            "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZRUNDH2TJRZRWL3DCH2PQ6KROWTPQ7AJ/"
          },
          {
            "name": "[debian-lts-announce] 20231023 [SECURITY] [DLA 3629-1] ceph security update",
            "tags": [
              "mailing-list",
              "x_transferred"
            ],
            "url": "https://lists.debian.org/debian-lts-announce/2023/10/msg00034.html"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "ceph",
          "vendor": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "ceph 14.2.21"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "A flaw was found in the Red Hat Ceph Storage RGW in versions before 14.2.21. When processing a GET Request for a swift URL that ends with two slashes it can cause the rgw to crash, resulting in a denial of service. The greatest threat to the system is of availability."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-20",
              "description": "CWE-20",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2023-10-23T18:06:19.527Z",
        "orgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
        "shortName": "redhat"
      },
      "references": [
        {
          "name": "[oss-security] 20210514 CVE-2021-3531: Ceph: RGW unauthenticated denial of service",
          "tags": [
            "mailing-list"
          ],
          "url": "http://www.openwall.com/lists/oss-security/2021/05/14/5"
        },
        {
          "name": "[oss-security] 20210517 Re: CVE-2021-3531: Ceph: RGW unauthenticated denial of service",
          "tags": [
            "mailing-list"
          ],
          "url": "http://www.openwall.com/lists/oss-security/2021/05/17/7"
        },
        {
          "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1955326"
        },
        {
          "name": "FEDORA-2021-ec414c5e18",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LPCJN2YDZCBMF4FOJXSTAADKFGEQEO7O/"
        },
        {
          "name": "FEDORA-2021-6e540b85b9",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FX5ZHI5L7FOHXOSEV3TYBAL66DMLJ7V5/"
        },
        {
          "name": "FEDORA-2021-1bf13db941",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZRUNDH2TJRZRWL3DCH2PQ6KROWTPQ7AJ/"
        },
        {
          "name": "[debian-lts-announce] 20231023 [SECURITY] [DLA 3629-1] ceph security update",
          "tags": [
            "mailing-list"
          ],
          "url": "https://lists.debian.org/debian-lts-announce/2023/10/msg00034.html"
        }
      ]
    }
  },
  "cveMetadata": {
    "assignerOrgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
    "assignerShortName": "redhat",
    "cveId": "CVE-2021-3531",
    "datePublished": "2021-05-18T00:00:00.000Z",
    "dateReserved": "2021-05-03T00:00:00.000Z",
    "dateUpdated": "2024-08-03T17:01:07.787Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2021-3531",
      "date": "2026-09-17",
      "epss": "0.02425",
      "percentile": "0.83403"
    },
    "fkie_nvd": {
      "configurations": "[{\"nodes\": [{\"operator\": \"OR\", \"negate\": false, \"cpeMatch\": [{\"vulnerable\": true, \"criteria\": \"cpe:2.3:a:redhat:ceph:*:*:*:*:*:*:*:*\", \"versionEndExcluding\": \"14.2.21\", \"matchCriteriaId\": \"B9DCC756-9F64-42E5-B79E-822655CF5A1B\"}, {\"vulnerable\": true, \"criteria\": \"cpe:2.3:a:redhat:ceph_storage:4.0:*:*:*:*:*:*:*\", \"matchCriteriaId\": \"D6E54096-5D45-4CB2-AC9A-DDB55BF2B94C\"}]}]}, {\"nodes\": [{\"operator\": \"OR\", \"negate\": false, \"cpeMatch\": [{\"vulnerable\": true, \"criteria\": \"cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*\", \"matchCriteriaId\": \"36D96259-24BD-44E2-96D9-78CE1D41F956\"}, {\"vulnerable\": true, \"criteria\": \"cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*\", \"matchCriteriaId\": \"E460AA51-FCDA-46B9-AE97-E6676AA5E194\"}, {\"vulnerable\": true, \"criteria\": \"cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*\", \"matchCriteriaId\": \"A930E247-0B43-43CB-98FF-6CE7B8189835\"}]}]}]",
      "descriptions": "[{\"lang\": \"en\", \"value\": \"A flaw was found in the Red Hat Ceph Storage RGW in versions before 14.2.21. When processing a GET Request for a swift URL that ends with two slashes it can cause the rgw to crash, resulting in a denial of service. The greatest threat to the system is of availability.\"}, {\"lang\": \"es\", \"value\": \"Se encontr\\u00f3 un fallo en Red Hat Ceph Storage RGW en versiones anteriores a 14.2.21.\u0026#xa0;Cuando se procesa una petici\\u00f3n GET para una URL r\\u00e1pida que termina con dos barras, puede hacer que rgw pueda bloquearse, resultando en una denegaci\\u00f3n de servicio.\u0026#xa0;La mayor amenaza para el sistema es la disponibilidad\"}]",
      "id": "CVE-2021-3531",
      "lastModified": "2024-11-21T06:21:46.740",
      "metrics": "{\"cvssMetricV31\": [{\"source\": \"nvd@nist.gov\", \"type\": \"Primary\", \"cvssData\": {\"version\": \"3.1\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L\", \"baseScore\": 5.3, \"baseSeverity\": \"MEDIUM\", \"attackVector\": \"NETWORK\", \"attackComplexity\": \"LOW\", \"privilegesRequired\": \"NONE\", \"userInteraction\": \"NONE\", \"scope\": \"UNCHANGED\", \"confidentialityImpact\": \"NONE\", \"integrityImpact\": \"NONE\", \"availabilityImpact\": \"LOW\"}, \"exploitabilityScore\": 3.9, \"impactScore\": 1.4}], \"cvssMetricV2\": [{\"source\": \"nvd@nist.gov\", \"type\": \"Primary\", \"cvssData\": {\"version\": \"2.0\", \"vectorString\": \"AV:N/AC:L/Au:N/C:N/I:N/A:P\", \"baseScore\": 5.0, \"accessVector\": \"NETWORK\", \"accessComplexity\": \"LOW\", \"authentication\": \"NONE\", \"confidentialityImpact\": \"NONE\", \"integrityImpact\": \"NONE\", \"availabilityImpact\": \"PARTIAL\"}, \"baseSeverity\": \"MEDIUM\", \"exploitabilityScore\": 10.0, \"impactScore\": 2.9, \"acInsufInfo\": false, \"obtainAllPrivilege\": false, \"obtainUserPrivilege\": false, \"obtainOtherPrivilege\": false, \"userInteractionRequired\": false}]}",
      "published": "2021-05-18T12:15:08.080",
      "references": "[{\"url\": \"http://www.openwall.com/lists/oss-security/2021/05/14/5\", \"source\": \"secalert@redhat.com\", \"tags\": [\"Mailing List\", \"Patch\", \"Third Party Advisory\"]}, {\"url\": \"http://www.openwall.com/lists/oss-security/2021/05/17/7\", \"source\": \"secalert@redhat.com\", \"tags\": [\"Mailing List\", \"Patch\", \"Third Party Advisory\"]}, {\"url\": \"https://bugzilla.redhat.com/show_bug.cgi?id=1955326\", \"source\": \"secalert@redhat.com\", \"tags\": [\"Issue Tracking\", \"Patch\", \"Vendor Advisory\"]}, {\"url\": \"https://lists.debian.org/debian-lts-announce/2023/10/msg00034.html\", \"source\": \"secalert@redhat.com\"}, {\"url\": \"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FX5ZHI5L7FOHXOSEV3TYBAL66DMLJ7V5/\", \"source\": \"secalert@redhat.com\"}, {\"url\": \"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LPCJN2YDZCBMF4FOJXSTAADKFGEQEO7O/\", \"source\": \"secalert@redhat.com\"}, {\"url\": \"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZRUNDH2TJRZRWL3DCH2PQ6KROWTPQ7AJ/\", \"source\": \"secalert@redhat.com\"}, {\"url\": \"http://www.openwall.com/lists/oss-security/2021/05/14/5\", \"source\": \"af854a3a-2127-422b-91ae-364da2661108\", \"tags\": [\"Mailing List\", \"Patch\", \"Third Party Advisory\"]}, {\"url\": \"http://www.openwall.com/lists/oss-security/2021/05/17/7\", \"source\": \"af854a3a-2127-422b-91ae-364da2661108\", \"tags\": [\"Mailing List\", \"Patch\", \"Third Party Advisory\"]}, {\"url\": \"https://bugzilla.redhat.com/show_bug.cgi?id=1955326\", \"source\": \"af854a3a-2127-422b-91ae-364da2661108\", \"tags\": [\"Issue Tracking\", \"Patch\", \"Vendor Advisory\"]}, {\"url\": \"https://lists.debian.org/debian-lts-announce/2023/10/msg00034.html\", \"source\": \"af854a3a-2127-422b-91ae-364da2661108\"}, {\"url\": \"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FX5ZHI5L7FOHXOSEV3TYBAL66DMLJ7V5/\", \"source\": \"af854a3a-2127-422b-91ae-364da2661108\"}, {\"url\": \"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LPCJN2YDZCBMF4FOJXSTAADKFGEQEO7O/\", \"source\": \"af854a3a-2127-422b-91ae-364da2661108\"}, {\"url\": \"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZRUNDH2TJRZRWL3DCH2PQ6KROWTPQ7AJ/\", \"source\": \"af854a3a-2127-422b-91ae-364da2661108\"}]",
      "sourceIdentifier": "secalert@redhat.com",
      "vulnStatus": "Modified",
      "weaknesses": "[{\"source\": \"secalert@redhat.com\", \"type\": \"Secondary\", \"description\": [{\"lang\": \"en\", \"value\": \"CWE-20\"}]}, {\"source\": \"nvd@nist.gov\", \"type\": \"Primary\", \"description\": [{\"lang\": \"en\", \"value\": \"CWE-617\"}]}]"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2021-3531\",\"sourceIdentifier\":\"secalert@redhat.com\",\"published\":\"2021-05-18T12:15:08.080\",\"lastModified\":\"2024-11-21T06:21:46.740\",\"vulnStatus\":\"Modified\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"A flaw was found in the Red Hat Ceph Storage RGW in versions before 14.2.21. When processing a GET Request for a swift URL that ends with two slashes it can cause the rgw to crash, resulting in a denial of service. The greatest threat to the system is of availability.\"},{\"lang\":\"es\",\"value\":\"Se encontr\u00f3 un fallo en Red Hat Ceph Storage RGW en versiones anteriores a 14.2.21.\u0026#xa0;Cuando se procesa una petici\u00f3n GET para una URL r\u00e1pida que termina con dos barras, puede hacer que rgw pueda bloquearse, resultando en una denegaci\u00f3n de servicio.\u0026#xa0;La mayor amenaza para el sistema es la disponibilidad\"}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L\",\"baseScore\":5.3,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"LOW\"},\"exploitabilityScore\":3.9,\"impactScore\":1.4}],\"cvssMetricV2\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"2.0\",\"vectorString\":\"AV:N/AC:L/Au:N/C:N/I:N/A:P\",\"baseScore\":5.0,\"accessVector\":\"NETWORK\",\"accessComplexity\":\"LOW\",\"authentication\":\"NONE\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"PARTIAL\"},\"baseSeverity\":\"MEDIUM\",\"exploitabilityScore\":10.0,\"impactScore\":2.9,\"acInsufInfo\":false,\"obtainAllPrivilege\":false,\"obtainUserPrivilege\":false,\"obtainOtherPrivilege\":false,\"userInteractionRequired\":false}]},\"weaknesses\":[{\"source\":\"secalert@redhat.com\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-20\"}]},{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-617\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:redhat:ceph:*:*:*:*:*:*:*:*\",\"versionEndExcluding\":\"14.2.21\",\"matchCriteriaId\":\"B9DCC756-9F64-42E5-B79E-822655CF5A1B\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:redhat:ceph_storage:4.0:*:*:*:*:*:*:*\",\"matchCriteriaId\":\"D6E54096-5D45-4CB2-AC9A-DDB55BF2B94C\"}]}]},{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*\",\"matchCriteriaId\":\"36D96259-24BD-44E2-96D9-78CE1D41F956\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*\",\"matchCriteriaId\":\"E460AA51-FCDA-46B9-AE97-E6676AA5E194\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*\",\"matchCriteriaId\":\"A930E247-0B43-43CB-98FF-6CE7B8189835\"}]}]}],\"references\":[{\"url\":\"http://www.openwall.com/lists/oss-security/2021/05/14/5\",\"source\":\"secalert@redhat.com\",\"tags\":[\"Mailing List\",\"Patch\",\"Third Party Advisory\"]},{\"url\":\"http://www.openwall.com/lists/oss-security/2021/05/17/7\",\"source\":\"secalert@redhat.com\",\"tags\":[\"Mailing List\",\"Patch\",\"Third Party Advisory\"]},{\"url\":\"https://bugzilla.redhat.com/show_bug.cgi?id=1955326\",\"source\":\"secalert@redhat.com\",\"tags\":[\"Issue Tracking\",\"Patch\",\"Vendor Advisory\"]},{\"url\":\"https://lists.debian.org/debian-lts-announce/2023/10/msg00034.html\",\"source\":\"secalert@redhat.com\"},{\"url\":\"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FX5ZHI5L7FOHXOSEV3TYBAL66DMLJ7V5/\",\"source\":\"secalert@redhat.com\"},{\"url\":\"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LPCJN2YDZCBMF4FOJXSTAADKFGEQEO7O/\",\"source\":\"secalert@redhat.com\"},{\"url\":\"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZRUNDH2TJRZRWL3DCH2PQ6KROWTPQ7AJ/\",\"source\":\"secalert@redhat.com\"},{\"url\":\"http://www.openwall.com/lists/oss-security/2021/05/14/5\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Mailing List\",\"Patch\",\"Third Party Advisory\"]},{\"url\":\"http://www.openwall.com/lists/oss-security/2021/05/17/7\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Mailing List\",\"Patch\",\"Third Party Advisory\"]},{\"url\":\"https://bugzilla.redhat.com/show_bug.cgi?id=1955326\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Issue Tracking\",\"Patch\",\"Vendor Advisory\"]},{\"url\":\"https://lists.debian.org/debian-lts-announce/2023/10/msg00034.html\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\"},{\"url\":\"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FX5ZHI5L7FOHXOSEV3TYBAL66DMLJ7V5/\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\"},{\"url\":\"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LPCJN2YDZCBMF4FOJXSTAADKFGEQEO7O/\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\"},{\"url\":\"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZRUNDH2TJRZRWL3DCH2PQ6KROWTPQ7AJ/\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2025-11-21T15:29:04+00:00",
      "cve": "CVE-2021-3531",
      "id": "CVE-2021-3531",
      "initial_release_date": "2021-05-13T00:00:00+00:00",
      "product_status:fixed": "555",
      "product_status:known_affected": "111",
      "product_status:known_not_affected": "28",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "ceph: RGW unauthenticated denial of service",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2021/cve-2021-3531.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "important",
      "current_release_date": "2026-09-02T02:26:41Z",
      "cve": "CVE-2021-3531",
      "id": "CVE-2021-3531",
      "initial_release_date": "2023-02-15T03:49:14Z",
      "product_status:known_not_affected": "491",
      "product_status:recommended": "1026",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2021-3531",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2021-3531.json",
      "version": "25"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.


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.