Vulnerability-Lookup

FKIE_CVE-2021-20090

Vulnerability from fkie_nvd - Published: 2021-04-29 15:15 - Updated: 2026-06-17 03:33

Severity

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

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.

References

URL	Tags
vulnreport@tenable.com	https://www.kb.cert.org/vuls/id/914124	Third Party Advisory, US Government Resource
vulnreport@tenable.com	https://www.secpod.com/blog/arcadyan-based-routers-and-modems-under-active-exploitation/	Exploit, Third Party Advisory
vulnreport@tenable.com	https://www.tenable.com/security/research/tra-2021-13	Exploit, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108	https://www.kb.cert.org/vuls/id/914124	Third Party Advisory, US Government Resource
af854a3a-2127-422b-91ae-364da2661108	https://www.secpod.com/blog/arcadyan-based-routers-and-modems-under-active-exploitation/	Exploit, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108	https://www.tenable.com/security/research/tra-2021-13	Exploit, Third Party Advisory
134c704f-9b21-4f2e-91b3-4a467353bcc0	https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-20090	US Government Resource

Impacted products

Vendor	Product	Version
buffalo	wsr-2533dhpl2-bk_firmware	*
buffalo	wsr-2533dhpl2-bk	-
buffalo	wsr-2533dhp3-bk_firmware	*
buffalo	wsr-2533dhp3-bk	-

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "Buffalo WSR-2533DHPL2, Buffalo WSR-2533DHP3",
          "vendor": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "WSR-2533DHPL2 \u003c=1.02, WSR-2533DHP3 \u003c= 1.24"
            }
          ]
        }
      ],
      "source": "vulnreport@tenable.com"
    }
  ],
  "cisaActionDue": "2021-11-17",
  "cisaExploitAdd": "2021-11-03",
  "cisaRequiredAction": "Apply updates per vendor instructions.",
  "cisaVulnerabilityName": "Arcadyan Buffalo Firmware Path Traversal Vulnerability",
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:buffalo:wsr-2533dhpl2-bk_firmware:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "D861729C-023B-4D73-8C4C-BF7E8B0B7045",
              "versionEndIncluding": "1.02",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        },
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:h:buffalo:wsr-2533dhpl2-bk:-:*:*:*:*:*:*:*",
              "matchCriteriaId": "1B03FA14-33E3-44D2-8165-197CB446F2D2",
              "vulnerable": false
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ],
      "operator": "AND"
    },
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:buffalo:wsr-2533dhp3-bk_firmware:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "63232EC8-B2B8-4867-93DB-C0C5147E2730",
              "versionEndIncluding": "1.24",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        },
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:h:buffalo:wsr-2533dhp3-bk:-:*:*:*:*:*:*:*",
              "matchCriteriaId": "7AA91D93-E2B9-4415-B541-1968F1F39814",
              "vulnerable": false
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ],
      "operator": "AND"
    }
  ],
  "cveTags": [],
  "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."
    },
    {
      "lang": "es",
      "value": "Una vulnerabilidad de salto de ruta en las interfaces web de Buffalo WSR-2533DHPL2 versi\u00f3n de firmware anterior a 1.02 e incluy\u00e9ndola y WSR-2533DHP3 versi\u00f3n de firmware anterior a 1.24 e incluy\u00e9ndola, podr\u00eda permitir a atacantes remotos no autenticados omitir la autenticaci\u00f3n"
    }
  ],
  "id": "CVE-2021-20090",
  "lastModified": "2026-06-17T03:33:15.487",
  "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"
      },
      {
        "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": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2021-20090",
          "options": [
            {
              "exploitation": "active"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2025-02-06T20:25:22.891349Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2021-04-29T15:15:10.630",
  "references": [
    {
      "source": "vulnreport@tenable.com",
      "tags": [
        "Third Party Advisory",
        "US Government Resource"
      ],
      "url": "https://www.kb.cert.org/vuls/id/914124"
    },
    {
      "source": "vulnreport@tenable.com",
      "tags": [
        "Exploit",
        "Third Party Advisory"
      ],
      "url": "https://www.secpod.com/blog/arcadyan-based-routers-and-modems-under-active-exploitation/"
    },
    {
      "source": "vulnreport@tenable.com",
      "tags": [
        "Exploit",
        "Third Party Advisory"
      ],
      "url": "https://www.tenable.com/security/research/tra-2021-13"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Third Party Advisory",
        "US Government Resource"
      ],
      "url": "https://www.kb.cert.org/vuls/id/914124"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Exploit",
        "Third Party Advisory"
      ],
      "url": "https://www.secpod.com/blog/arcadyan-based-routers-and-modems-under-active-exploitation/"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Exploit",
        "Third Party Advisory"
      ],
      "url": "https://www.tenable.com/security/research/tra-2021-13"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "tags": [
        "US Government Resource"
      ],
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-20090"
    }
  ],
  "sourceIdentifier": "vulnreport@tenable.com",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-22"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    },
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-22"
        }
      ],
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "type": "Secondary"
    }
  ]
}

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

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

Summary

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 Scorecard

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",
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        },
        "references": [
          {
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            "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.

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FKIE_CVE-2021-20090

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

Tags

Sightings

Nomenclature

Related by attack behaviour