Vulnerability-Lookup

FKIE_CVE-2021-23435

Vulnerability from fkie_nvd - Published: 2021-09-12 20:15 - Updated: 2026-06-17 03:38

Severity

7.6 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H
6.1 (Medium) - CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Summary

This affects the package clearance before 2.5.0. The vulnerability can be possible when users are able to set the value of session[:return_to]. If the value used for return_to contains multiple leading slashes (/////example.com) the user ends up being redirected to the external domain that comes after the slashes (http://example.com).

References

URL	Tags
report@snyk.io	https://github.com/thoughtbot/clearance/pull/945	Patch, Third Party Advisory
report@snyk.io	https://snyk.io/vuln/SNYK-RUBY-CLEARANCE-1577284	Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108	https://github.com/thoughtbot/clearance/pull/945	Patch, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108	https://snyk.io/vuln/SNYK-RUBY-CLEARANCE-1577284	Third Party Advisory

Impacted products

	Vendor	Product	Version
	thoughtbot	clearance	*

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "clearance",
          "vendor": "n/a",
          "versions": [
            {
              "lessThan": "2.5.0",
              "status": "affected",
              "version": "unspecified",
              "versionType": "custom"
            }
          ]
        }
      ],
      "source": "report@snyk.io"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:thoughtbot:clearance:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "DA5DD45E-7578-4DD7-9105-F2CBC8A35649",
              "versionEndExcluding": "2.5.0",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "This affects the package clearance before 2.5.0. The vulnerability can be possible when users are able to set the value of session[:return_to]. If the value used for return_to contains multiple leading slashes (/////example.com) the user ends up being redirected to the external domain that comes after the slashes (http://example.com)."
    },
    {
      "lang": "es",
      "value": "Esto afecta al paquete clearance versiones anteriores a 2.5.0. La vulnerabilidad puede ser posible cuando los usuarios son capaces de establecer el valor de session[:return_to]. Si el valor usado para return_to contiene m\u00faltiples barras inclinadas (/////example.com) el usuario acaba siendo redirigido al dominio externo que viene despu\u00e9s de las barras (http://example.com)"
    }
  ],
  "id": "CVE-2021-23435",
  "lastModified": "2026-06-17T03:38:45.490",
  "metrics": {
    "cvssMetricV2": [
      {
        "acInsufInfo": false,
        "baseSeverity": "MEDIUM",
        "cvssData": {
          "accessComplexity": "MEDIUM",
          "accessVector": "NETWORK",
          "authentication": "NONE",
          "availabilityImpact": "NONE",
          "baseScore": 5.8,
          "confidentialityImpact": "PARTIAL",
          "integrityImpact": "PARTIAL",
          "vectorString": "AV:N/AC:M/Au:N/C:P/I:P/A:N",
          "version": "2.0"
        },
        "exploitabilityScore": 8.6,
        "impactScore": 4.9,
        "obtainAllPrivilege": false,
        "obtainOtherPrivilege": false,
        "obtainUserPrivilege": false,
        "source": "nvd@nist.gov",
        "type": "Primary",
        "userInteractionRequired": true
      }
    ],
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 7.6,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "LOW",
          "integrityImpact": "LOW",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "REQUIRED",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 4.7,
        "source": "report@snyk.io",
        "type": "Secondary"
      },
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 6.1,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "LOW",
          "integrityImpact": "LOW",
          "privilegesRequired": "NONE",
          "scope": "CHANGED",
          "userInteraction": "REQUIRED",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 2.7,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ]
  },
  "published": "2021-09-12T20:15:07.443",
  "references": [
    {
      "source": "report@snyk.io",
      "tags": [
        "Patch",
        "Third Party Advisory"
      ],
      "url": "https://github.com/thoughtbot/clearance/pull/945"
    },
    {
      "source": "report@snyk.io",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://snyk.io/vuln/SNYK-RUBY-CLEARANCE-1577284"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Patch",
        "Third Party Advisory"
      ],
      "url": "https://github.com/thoughtbot/clearance/pull/945"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://snyk.io/vuln/SNYK-RUBY-CLEARANCE-1577284"
    }
  ],
  "sourceIdentifier": "report@snyk.io",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-601"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}

CVE-2021-23435 (GCVE-0-2021-23435)

Vulnerability from cvelistv5 – Published: 2021-09-12 20:05 – Updated: 2024-09-16 23:55

Title

Open Redirect

Summary

Severity

7.6 (High)


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

CWE

Open Redirect

Assigner

snyk mitre root

References

2 references

URL	Tags
https://snyk.io/vuln/SNYK-RUBY-CLEARANCE-1577284	x_refsource_MISC
https://github.com/thoughtbot/clearance/pull/945	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
n/a	clearance	Affected: unspecified , < 2.5.0 (custom)

Date Public

2021-09-12 00:00

Credits

Snyk Security Team

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-03T19:05:56.218Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://snyk.io/vuln/SNYK-RUBY-CLEARANCE-1577284"
          },
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://github.com/thoughtbot/clearance/pull/945"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "clearance",
          "vendor": "n/a",
          "versions": [
            {
              "lessThan": "2.5.0",
              "status": "affected",
              "version": "unspecified",
              "versionType": "custom"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "value": "Snyk Security Team"
        }
      ],
      "datePublic": "2021-09-12T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "This affects the package clearance before 2.5.0. The vulnerability can be possible when users are able to set the value of session[:return_to]. If the value used for return_to contains multiple leading slashes (/////example.com) the user ends up being redirected to the external domain that comes after the slashes (http://example.com)."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 7.6,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "LOW",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "Open Redirect",
              "lang": "en",
              "type": "text"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2021-09-12T20:05:10.000Z",
        "orgId": "bae035ff-b466-4ff4-94d0-fc9efd9e1730",
        "shortName": "snyk"
      },
      "references": [
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://snyk.io/vuln/SNYK-RUBY-CLEARANCE-1577284"
        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/thoughtbot/clearance/pull/945"
        }
      ],
      "title": "Open Redirect",
      "x_legacyV4Record": {
        "CVE_data_meta": {
          "ASSIGNER": "report@snyk.io",
          "DATE_PUBLIC": "2021-09-12T20:00:23.031648Z",
          "ID": "CVE-2021-23435",
          "STATE": "PUBLIC",
          "TITLE": "Open Redirect"
        },
        "affects": {
          "vendor": {
            "vendor_data": [
              {
                "product": {
                  "product_data": [
                    {
                      "product_name": "clearance",
                      "version": {
                        "version_data": [
                          {
                            "version_affected": "\u003c",
                            "version_value": "2.5.0"
                          }
                        ]
                      }
                    }
                  ]
                },
                "vendor_name": "n/a"
              }
            ]
          }
        },
        "credit": [
          {
            "lang": "eng",
            "value": "Snyk Security Team"
          }
        ],
        "data_format": "MITRE",
        "data_type": "CVE",
        "data_version": "4.0",
        "description": {
          "description_data": [
            {
              "lang": "eng",
              "value": "This affects the package clearance before 2.5.0. The vulnerability can be possible when users are able to set the value of session[:return_to]. If the value used for return_to contains multiple leading slashes (/////example.com) the user ends up being redirected to the external domain that comes after the slashes (http://example.com)."
            }
          ]
        },
        "impact": {
          "cvss": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 7.6,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "LOW",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H",
            "version": "3.1"
          }
        },
        "problemtype": {
          "problemtype_data": [
            {
              "description": [
                {
                  "lang": "eng",
                  "value": "Open Redirect"
                }
              ]
            }
          ]
        },
        "references": {
          "reference_data": [
            {
              "name": "https://snyk.io/vuln/SNYK-RUBY-CLEARANCE-1577284",
              "refsource": "MISC",
              "url": "https://snyk.io/vuln/SNYK-RUBY-CLEARANCE-1577284"
            },
            {
              "name": "https://github.com/thoughtbot/clearance/pull/945",
              "refsource": "MISC",
              "url": "https://github.com/thoughtbot/clearance/pull/945"
            }
          ]
        }
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "bae035ff-b466-4ff4-94d0-fc9efd9e1730",
    "assignerShortName": "snyk",
    "cveId": "CVE-2021-23435",
    "datePublished": "2021-09-12T20:05:10.404Z",
    "dateReserved": "2021-01-08T00:00:00.000Z",
    "dateUpdated": "2024-09-16T23:55:46.556Z",
    "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.

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.