Vulnerability-Lookup

BDU:2021-03989 (CVE-2021-20090)

Vulnerability from fstec – Published: 2021-08-10 – Updated: 2021-08-11 – View on bdu.fstec.ru Exploit publicly available Yes Fixed

Title

Уязвимость веб-интерфейса микропрограммного обеспечения Arcadyan маршрутизаторов Buffalo, позволяющая нарушителю обойти процесс аутентификации

Summary

Уязвимость веб-интерфейса микропрограммного обеспечения Arcadyan маршрутизаторов Buffalo связана с возможностью обхода пути к каталогу. Эксплуатация уязвимости может позволить нарушителю, действующему удаленно, обойти процесс аутентификации

Severity

10.0 (High) CVSS 2.0


                      
                        AV:N/AC:L/Au:N/C:C/I:C/A:C

9.8 (Critical) CVSS 3.0


                      
                        CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Class

Code vulnerability

Status

Confirmed by the vendor

Exploitation

Authentication bypass

Incidents

Yes

Remediation

Software update

CWE

CWE-22 - Неверное ограничение имени пути к каталогу с ограниченным доступом («Обход пути»)

Aliases

CVE-2021-20090

References

3 references

URL
https://www.tenable.com/security/research/tra-2021-13
https://www.kb.cert.org/vuls/id/914124
https://nvd.nist.gov/vuln/detail/CVE-2021-20090

Impacted products

6 products from 2 vendors

Vendors

Buffalo Technology, Arcadyan

Products

Buffalo wsr-2533dhpl2-bk, Buffalo wsr-2533dhp3-bk, ARV7519, VRV9517, VGV7519, VRV9518

Versions

до 1.02 (Buffalo wsr-2533dhpl2-bk), до 1.24 (Buffalo wsr-2533dhp3-bk), 00.96.00.96.617ES (ARV7519), 6.00.17 build04 (VRV9517), 3.01.116 (VGV7519), 1.01.00 build44 (VRV9518)

Product types

Network appliance software

Mitigations

Использование рекомендаций: https://www.tenable.com/security/research/tra-2021-13

JSON

To clipboard

{
  "CVSS 2.0": "AV:N/AC:L/Au:N/C:C/I:C/A:C",
  "CVSS 3.0": "AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
  "CVSS 4.0": null,
  "remediation_\u0418\u0434\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0442\u043e\u0440": null,
  "remediation_\u041d\u0430\u0438\u043c\u0435\u043d\u043e\u0432\u0430\u043d\u0438\u0435": null,
  "\u0412\u0435\u043d\u0434\u043e\u0440 \u041f\u041e": "Buffalo Technology, Arcadyan",
  "\u0412\u0435\u0440\u0441\u0438\u044f \u041f\u041e": "\u0434\u043e 1.02 (Buffalo wsr-2533dhpl2-bk), \u0434\u043e 1.24 (Buffalo wsr-2533dhp3-bk), 00.96.00.96.617ES (ARV7519), 6.00.17 build04 (VRV9517), 3.01.116 (VGV7519), 1.01.00 build44 (VRV9518)",
  "\u0412\u043e\u0437\u043c\u043e\u0436\u043d\u044b\u0435 \u043c\u0435\u0440\u044b \u043f\u043e \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0438\u044e": "\u0418\u0441\u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u043d\u0438\u0435 \u0440\u0435\u043a\u043e\u043c\u0435\u043d\u0434\u0430\u0446\u0438\u0439:\nhttps://www.tenable.com/security/research/tra-2021-13",
  "\u0414\u0430\u0442\u0430 \u0432\u044b\u044f\u0432\u043b\u0435\u043d\u0438\u044f": "20.07.2021",
  "\u0414\u0430\u0442\u0430 \u043f\u043e\u0441\u043b\u0435\u0434\u043d\u0435\u0433\u043e \u043e\u0431\u043d\u043e\u0432\u043b\u0435\u043d\u0438\u044f": "11.08.2021",
  "\u0414\u0430\u0442\u0430 \u043f\u0443\u0431\u043b\u0438\u043a\u0430\u0446\u0438\u0438": "10.08.2021",
  "\u0418\u0434\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0442\u043e\u0440": "BDU:2021-03989",
  "\u0418\u0434\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0442\u043e\u0440\u044b \u0434\u0440\u0443\u0433\u0438\u0445 \u0441\u0438\u0441\u0442\u0435\u043c \u043e\u043f\u0438\u0441\u0430\u043d\u0438\u0439 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "CVE-2021-20090",
  "\u0418\u043d\u0444\u043e\u0440\u043c\u0430\u0446\u0438\u044f \u043e\u0431 \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0438\u0438": "\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0430",
  "\u041a\u043b\u0430\u0441\u0441 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u043a\u043e\u0434\u0430",
  "\u041d\u0430\u0437\u0432\u0430\u043d\u0438\u0435 \u041f\u041e": "Buffalo wsr-2533dhpl2-bk, Buffalo wsr-2533dhp3-bk, ARV7519, VRV9517, VGV7519, VRV9518",
  "\u041d\u0430\u0438\u043c\u0435\u043d\u043e\u0432\u0430\u043d\u0438\u0435 \u041e\u0421 \u0438 \u0442\u0438\u043f \u0430\u043f\u043f\u0430\u0440\u0430\u0442\u043d\u043e\u0439 \u043f\u043b\u0430\u0442\u0444\u043e\u0440\u043c\u044b": null,
  "\u041d\u0430\u0438\u043c\u0435\u043d\u043e\u0432\u0430\u043d\u0438\u0435 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u0432\u0435\u0431-\u0438\u043d\u0442\u0435\u0440\u0444\u0435\u0439\u0441\u0430 \u043c\u0438\u043a\u0440\u043e\u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u043e\u0433\u043e \u043e\u0431\u0435\u0441\u043f\u0435\u0447\u0435\u043d\u0438\u044f Arcadyan \u043c\u0430\u0440\u0448\u0440\u0443\u0442\u0438\u0437\u0430\u0442\u043e\u0440\u043e\u0432 Buffalo, \u043f\u043e\u0437\u0432\u043e\u043b\u044f\u044e\u0449\u0430\u044f \u043d\u0430\u0440\u0443\u0448\u0438\u0442\u0435\u043b\u044e \u043e\u0431\u043e\u0439\u0442\u0438 \u043f\u0440\u043e\u0446\u0435\u0441\u0441 \u0430\u0443\u0442\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0446\u0438\u0438",
  "\u041d\u0430\u043b\u0438\u0447\u0438\u0435 \u044d\u043a\u0441\u043f\u043b\u043e\u0439\u0442\u0430": "\u0421\u0443\u0449\u0435\u0441\u0442\u0432\u0443\u0435\u0442 \u0432 \u043e\u0442\u043a\u0440\u044b\u0442\u043e\u043c \u0434\u043e\u0441\u0442\u0443\u043f\u0435",
  "\u041e\u043f\u0438\u0441\u0430\u043d\u0438\u0435 \u043e\u0448\u0438\u0431\u043a\u0438 CWE": "\u041d\u0435\u0432\u0435\u0440\u043d\u043e\u0435 \u043e\u0433\u0440\u0430\u043d\u0438\u0447\u0435\u043d\u0438\u0435 \u0438\u043c\u0435\u043d\u0438 \u043f\u0443\u0442\u0438 \u043a \u043a\u0430\u0442\u0430\u043b\u043e\u0433\u0443 \u0441 \u043e\u0433\u0440\u0430\u043d\u0438\u0447\u0435\u043d\u043d\u044b\u043c \u0434\u043e\u0441\u0442\u0443\u043f\u043e\u043c (\u00ab\u041e\u0431\u0445\u043e\u0434 \u043f\u0443\u0442\u0438\u00bb) (CWE-22)",
  "\u041e\u043f\u0438\u0441\u0430\u043d\u0438\u0435 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u0432\u0435\u0431-\u0438\u043d\u0442\u0435\u0440\u0444\u0435\u0439\u0441\u0430 \u043c\u0438\u043a\u0440\u043e\u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u043e\u0433\u043e \u043e\u0431\u0435\u0441\u043f\u0435\u0447\u0435\u043d\u0438\u044f Arcadyan \u043c\u0430\u0440\u0448\u0440\u0443\u0442\u0438\u0437\u0430\u0442\u043e\u0440\u043e\u0432 Buffalo \u0441\u0432\u044f\u0437\u0430\u043d\u0430 \u0441 \u0432\u043e\u0437\u043c\u043e\u0436\u043d\u043e\u0441\u0442\u044c\u044e \u043e\u0431\u0445\u043e\u0434\u0430 \u043f\u0443\u0442\u0438 \u043a \u043a\u0430\u0442\u0430\u043b\u043e\u0433\u0443. \u042d\u043a\u0441\u043f\u043b\u0443\u0430\u0442\u0430\u0446\u0438\u044f \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438 \u043c\u043e\u0436\u0435\u0442  \u043f\u043e\u0437\u0432\u043e\u043b\u0438\u0442\u044c  \u043d\u0430\u0440\u0443\u0448\u0438\u0442\u0435\u043b\u044e, \u0434\u0435\u0439\u0441\u0442\u0432\u0443\u044e\u0449\u0435\u043c\u0443 \u0443\u0434\u0430\u043b\u0435\u043d\u043d\u043e, \u043e\u0431\u043e\u0439\u0442\u0438 \u043f\u0440\u043e\u0446\u0435\u0441\u0441 \u0430\u0443\u0442\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0446\u0438\u0438",
  "\u041f\u043e\u0441\u043b\u0435\u0434\u0441\u0442\u0432\u0438\u044f \u044d\u043a\u0441\u043f\u043b\u0443\u0430\u0442\u0430\u0446\u0438\u0438 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": null,
  "\u041f\u0440\u043e\u0447\u0430\u044f \u0438\u043d\u0444\u043e\u0440\u043c\u0430\u0446\u0438\u044f": null,
  "\u0421\u0432\u044f\u0437\u044c \u0441 \u0438\u043d\u0446\u0438\u0434\u0435\u043d\u0442\u0430\u043c\u0438 \u0418\u0411": "\u0414\u0430",
  "\u0421\u043e\u0441\u0442\u043e\u044f\u043d\u0438\u0435 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u041e\u043f\u0443\u0431\u043b\u0438\u043a\u043e\u0432\u0430\u043d\u0430",
  "\u0421\u043f\u043e\u0441\u043e\u0431 \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0438\u044f": "\u041e\u0431\u043d\u043e\u0432\u043b\u0435\u043d\u0438\u0435 \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u043e\u0433\u043e \u043e\u0431\u0435\u0441\u043f\u0435\u0447\u0435\u043d\u0438\u044f",
  "\u0421\u043f\u043e\u0441\u043e\u0431 \u044d\u043a\u0441\u043f\u043b\u0443\u0430\u0442\u0430\u0446\u0438\u0438": "\u041d\u0430\u0440\u0443\u0448\u0435\u043d\u0438\u0435 \u0430\u0443\u0442\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0446\u0438\u0438",
  "\u0421\u0441\u044b\u043b\u043a\u0438 \u043d\u0430 \u0438\u0441\u0442\u043e\u0447\u043d\u0438\u043a\u0438": "https://www.tenable.com/security/research/tra-2021-13\nhttps://www.kb.cert.org/vuls/id/914124\nhttps://nvd.nist.gov/vuln/detail/CVE-2021-20090",
  "\u0421\u0442\u0430\u0442\u0443\u0441 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u041f\u043e\u0434\u0442\u0432\u0435\u0440\u0436\u0434\u0435\u043d\u0430 \u043f\u0440\u043e\u0438\u0437\u0432\u043e\u0434\u0438\u0442\u0435\u043b\u0435\u043c",
  "\u0422\u0438\u043f \u041f\u041e": "\u041f\u041e \u0441\u0435\u0442\u0435\u0432\u043e\u0433\u043e \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u043e-\u0430\u043f\u043f\u0430\u0440\u0430\u0442\u043d\u043e\u0433\u043e \u0441\u0440\u0435\u0434\u0441\u0442\u0432\u0430",
  "\u0422\u0438\u043f \u043e\u0448\u0438\u0431\u043a\u0438 CWE": "CWE-22",
  "\u0423\u0440\u043e\u0432\u0435\u043d\u044c \u043e\u043f\u0430\u0441\u043d\u043e\u0441\u0442\u0438 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u041a\u0440\u0438\u0442\u0438\u0447\u0435\u0441\u043a\u0438\u0439 \u0443\u0440\u043e\u0432\u0435\u043d\u044c \u043e\u043f\u0430\u0441\u043d\u043e\u0441\u0442\u0438 (\u0431\u0430\u0437\u043e\u0432\u0430\u044f \u043e\u0446\u0435\u043d\u043a\u0430 CVSS 2.0 \u0441\u043e\u0441\u0442\u0430\u0432\u043b\u044f\u0435\u0442 10)\n\u041a\u0440\u0438\u0442\u0438\u0447\u0435\u0441\u043a\u0438\u0439 \u0443\u0440\u043e\u0432\u0435\u043d\u044c \u043e\u043f\u0430\u0441\u043d\u043e\u0441\u0442\u0438 (\u0431\u0430\u0437\u043e\u0432\u0430\u044f \u043e\u0446\u0435\u043d\u043a\u0430 CVSS 3.0 \u0441\u043e\u0441\u0442\u0430\u0432\u043b\u044f\u0435\u0442 9,8)"
}

CVE-2021-20090 (GCVE-0-2021-20090)

Vulnerability from cvelistv5 – Published: 2021-04-29 00:00 – Updated: 2025-10-21 23:25

Summary

A path traversal vulnerability in the web interfaces of Buffalo WSR-2533DHPL2 firmware version <= 1.02 and WSR-2533DHP3 firmware version <= 1.24 could allow unauthenticated remote attackers to bypass authentication.

Severity

9.8 (Critical)


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

SSVC

Exploitation: active Automatable: yes Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2025-02-06 20:25 UTC

CWE

Path Traversal
CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Assigner

tenable mitre root

References

4 references

URL	Tags
https://www.tenable.com/security/research/tra-2021-13
https://www.kb.cert.org/vuls/id/914124	third-party-advisory
https://www.secpod.com/blog/arcadyan-based-router…
https://www.cisa.gov/known-exploited-vulnerabilit…	government-resource

Impacted products

1 product

Vendor	Product	Version
n/a	Buffalo WSR-2533DHPL2, Buffalo WSR-2533DHP3	Affected: WSR-2533DHPL2 <=1.02, WSR-2533DHP3 <= 1.24

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-03T17:30:07.572Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://www.tenable.com/security/research/tra-2021-13"
          },
          {
            "name": "VU#914124",
            "tags": [
              "third-party-advisory",
              "x_transferred"
            ],
            "url": "https://www.kb.cert.org/vuls/id/914124"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://www.secpod.com/blog/arcadyan-based-routers-and-modems-under-active-exploitation/"
          }
        ],
        "title": "CVE Program Container"
      },
      {
        "metrics": [
          {
            "cvssV3_1": {
              "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"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2021-20090",
                "options": [
                  {
                    "Exploitation": "active"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2025-02-06T20:25:22.891349Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          },
          {
            "other": {
              "content": {
                "dateAdded": "2021-11-03",
                "reference": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-20090"
              },
              "type": "kev"
            }
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "cweId": "CWE-22",
                "description": "CWE-22 Improper Limitation of a Pathname to a Restricted Directory (\u0027Path Traversal\u0027)",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2025-10-21T23:25:47.628Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "government-resource"
            ],
            "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-20090"
          }
        ],
        "timeline": [
          {
            "lang": "en",
            "time": "2021-11-03T00:00:00.000Z",
            "value": "CVE-2021-20090 added to CISA KEV"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "Buffalo WSR-2533DHPL2, Buffalo WSR-2533DHP3",
          "vendor": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "WSR-2533DHPL2 \u003c=1.02, WSR-2533DHP3 \u003c= 1.24"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "A path traversal vulnerability in the web interfaces of Buffalo WSR-2533DHPL2 firmware version \u003c= 1.02 and WSR-2533DHP3 firmware version \u003c= 1.24 could allow unauthenticated remote attackers to bypass authentication."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "Path Traversal",
              "lang": "en",
              "type": "text"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2023-10-18T11:29:20.400Z",
        "orgId": "5ac1ecc2-367a-4d16-a0b2-35d495ddd0be",
        "shortName": "tenable"
      },
      "references": [
        {
          "url": "https://www.tenable.com/security/research/tra-2021-13"
        },
        {
          "name": "VU#914124",
          "tags": [
            "third-party-advisory"
          ],
          "url": "https://www.kb.cert.org/vuls/id/914124"
        },
        {
          "url": "https://www.secpod.com/blog/arcadyan-based-routers-and-modems-under-active-exploitation/"
        }
      ]
    }
  },
  "cveMetadata": {
    "assignerOrgId": "5ac1ecc2-367a-4d16-a0b2-35d495ddd0be",
    "assignerShortName": "tenable",
    "cveId": "CVE-2021-20090",
    "datePublished": "2021-04-29T00:00:00.000Z",
    "dateReserved": "2020-12-17T00:00:00.000Z",
    "dateUpdated": "2025-10-21T23:25:47.628Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1"
}

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.

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.

Action not permitted

BDU:2021-03989 (CVE-2021-20090)

CVE-2021-20090 (GCVE-0-2021-20090)

Tags

Sightings

Nomenclature

Related by attack behaviour