github - ghsa-6qmf-fj6m-686c

GHSA-6QMF-FJ6M-686C

Vulnerability from github – Published: 2021-05-17 20:51 – Updated: 2024-09-20 21:06

Summary

Open Redirect in Flask-Security-Too

Details

Impact

Flask-Security allows redirects after many successful views (e.g. /login) by honoring the ?next query param. There is code in FS to validate that the url specified in the next parameter is either relative OR has the same netloc (network location) as the requesting URL.

This check utilizes Pythons urlsplit library. However many browsers are very lenient on the kind of URL they accept and 'fill in the blanks' when presented with a possibly incomplete URL. As a concrete example - setting http://login?next=\\github.com will pass FS's relative URL check however many browsers will gladly convert this to http://github.com. Thus an attacker could send such a link to an unwitting user, using a legitimate site and have it redirect to whatever site they want.

This is considered a low severity due to the fact that if Werkzeug by default ALWAYS ensures that the Location header is absolute - thus making this attack vector mute. It is possible for application writers to modify this default behavior by setting the 'autocorrect_location_header=False` which would then open up their application to this attack.

Patches

No patches as this time

Workarounds

If using Werkzeug, make sure to use the default Location header setting. If you can't - then use@app.after_request and write your own validation of the Location header if it is set.

References

No.

For more information

If you have any questions or comments about this advisory follow: https://github.com/Flask-Middleware/flask-security/issues/486

Thanks to Claroty (2021-0141) and @snoopysecurity for providing details and proof of concept.

Severity ?

3.1 (Low)


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

2.1 (Low)


                  
                    CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "Flask-Security-Too"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.1.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2021-32618"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-601"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2021-05-17T16:53:26Z",
    "nvd_published_at": null,
    "severity": "LOW"
  },
  "details": "### Impact\nFlask-Security allows redirects after many successful views (e.g. /login) by honoring the ?next query param. There is code in FS to validate that the url specified in the next parameter is either relative OR has the same netloc (network location) as the requesting  URL.\n\nThis check utilizes Pythons urlsplit library. However many browsers are very lenient on the kind of URL they accept and \u0027fill in the blanks\u0027 when presented with a possibly incomplete URL. As a concrete example - setting http://login?next=\\\\\\github.com\nwill pass FS\u0027s relative URL check however many browsers will gladly convert this to http://github.com. Thus an attacker could send such a link to an unwitting user, using a legitimate site and have it redirect to whatever site they want.\n\nThis is considered a low severity due to the fact that if Werkzeug by default ALWAYS ensures that the Location header is absolute - thus making this attack vector mute. It is possible for application writers to modify this default behavior by setting the \u0027autocorrect_location_header=False` which would then open up their application to this attack.\n\n### Patches\nNo patches as this time\n\n### Workarounds\nIf using Werkzeug, make sure to use the default Location header setting. If you can\u0027t - then use@app.after_request and write your own validation of the Location header if it is set.\n\n### References\nNo.\n\n### For more information\nIf you have any questions or comments about this advisory follow: https://github.com/Flask-Middleware/flask-security/issues/486\n\nThanks to Claroty (2021-0141) and @snoopysecurity for providing details and proof of concept.\n",
  "id": "GHSA-6qmf-fj6m-686c",
  "modified": "2024-09-20T21:06:55Z",
  "published": "2021-05-17T20:51:27Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2021-32618"
    },
    {
      "type": "WEB",
      "url": "https://github.com/Flask-Middleware/flask-security/commit/e39bb04615050448c1b8ba4caa7dacc0edd3e405"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/Flask-Middleware/flask-security"
    },
    {
      "type": "WEB",
      "url": "https://github.com/pypa/advisory-database/tree/main/vulns/flask-security-too/PYSEC-2021-123.yaml"
    },
    {
      "type": "WEB",
      "url": "https://web.archive.org/web/20210517211717/https://github.com/Flask-Middleware/flask-security/issues/486"
    },
    {
      "type": "WEB",
      "url": "https://web.archive.org/web/20211207121851/https://github.com/Flask-Middleware/flask-security/security/advisories/GHSA-6qmf-fj6m-686c"
    },
    {
      "type": "WEB",
      "url": "https://web.archive.org/web/20220410062740/https://github.com/Flask-Middleware/flask-security/pull/489"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Open Redirect in Flask-Security-Too"
}

PYSEC-2021-123

Vulnerability from pysec - Published: 2021-05-17 18:15 - Updated: 2021-08-25 04:30

Details

The Python "Flask-Security-Too" package is used for adding security features to your Flask application. It is an is an independently maintained version of Flask-Security based on the 3.0.0 version of Flask-Security. All versions of Flask-Security-Too allow redirects after many successful views (e.g. /login) by honoring the ?next query param. There is code in FS to validate that the url specified in the next parameter is either relative OR has the same netloc (network location) as the requesting URL. This check utilizes Pythons urlsplit library. However many browsers are very lenient on the kind of URL they accept and 'fill in the blanks' when presented with a possibly incomplete URL. As a concrete example - setting http://login?next=\\github.com will pass FS's relative URL check however many browsers will gladly convert this to http://github.com. Thus an attacker could send such a link to an unwitting user, using a legitimate site and have it redirect to whatever site they want. This is considered a low severity due to the fact that if Werkzeug is used (which is very common with Flask applications) as the WSGI layer, it by default ALWAYS ensures that the Location header is absolute - thus making this attack vector mute. It is possible for application writers to modify this default behavior by setting the autocorrect_location_header=False.

Impacted products

Name	purl
flask-security-too	pkg:pypi/flask-security-too

Aliases

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "flask-security-too",
        "purl": "pkg:pypi/flask-security-too"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.1.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.0.1",
        "3.0.1rc1",
        "3.0.1rc2",
        "3.0.1rc3",
        "3.0.2",
        "3.1.0rc1",
        "3.2.0",
        "3.2.0rc1",
        "3.2.0rc3",
        "3.2.0rc4",
        "3.3.0",
        "3.3.0rc1",
        "3.3.0rc2",
        "3.3.0rc3",
        "3.3.1",
        "3.3.2",
        "3.3.3",
        "3.4.0",
        "3.4.1",
        "3.4.2",
        "3.4.3",
        "3.4.4",
        "3.4.5",
        "4.0.0",
        "4.0.0rc1",
        "4.0.0rc2",
        "4.0.1"
      ]
    }
  ],
  "aliases": [
    "CVE-2021-32618",
    "GHSA-6qmf-fj6m-686c"
  ],
  "details": "The Python \"Flask-Security-Too\" package is used for adding security features to your Flask application. It is an is an independently maintained version of Flask-Security based on the 3.0.0 version of Flask-Security. All versions of Flask-Security-Too allow redirects after many successful views (e.g. /login) by honoring the ?next query param. There is code in FS to validate that the url specified in the next parameter is either relative OR has the same netloc (network location) as the requesting URL. This check utilizes Pythons urlsplit library. However many browsers are very lenient on the kind of URL they accept and \u0027fill in the blanks\u0027 when presented with a possibly incomplete URL. As a concrete example - setting http://login?next=\\\\\\github.com will pass FS\u0027s relative URL check however many browsers will gladly convert this to http://github.com. Thus an attacker could send such a link to an unwitting user, using a legitimate site and have it redirect to whatever site they want. This is considered a low severity due to the fact that if Werkzeug is used (which is very common with Flask applications) as the WSGI layer, it by default ALWAYS ensures that the Location header is absolute - thus making this attack vector mute. It is possible for application writers to modify this default behavior by setting the `autocorrect_location_header=False`.",
  "id": "PYSEC-2021-123",
  "modified": "2021-08-25T04:30:09.653075Z",
  "published": "2021-05-17T18:15:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://github.com/Flask-Middleware/flask-security/issues/486"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/Flask-Middleware/flask-security/security/advisories/GHSA-6qmf-fj6m-686c"
    }
  ]
}

CVE-2021-32618 (GCVE-0-2021-32618)

Vulnerability from cvelistv5 – Published: 2021-05-17 18:05 – Updated: 2024-08-03 23:25

Title

Open Redirect Vulnerability

Summary

The Python "Flask-Security-Too" package is used for adding security features to your Flask application. It is an is an independently maintained version of Flask-Security based on the 3.0.0 version of Flask-Security. All versions of Flask-Security-Too allow redirects after many successful views (e.g. /login) by honoring the ?next query param. There is code in FS to validate that the url specified in the next parameter is either relative OR has the same netloc (network location) as the requesting URL. This check utilizes Pythons urlsplit library. However many browsers are very lenient on the kind of URL they accept and 'fill in the blanks' when presented with a possibly incomplete URL. As a concrete example - setting http://login?next=\\\github.com will pass FS's relative URL check however many browsers will gladly convert this to http://github.com. Thus an attacker could send such a link to an unwitting user, using a legitimate site and have it redirect to whatever site they want. This is considered a low severity due to the fact that if Werkzeug is used (which is very common with Flask applications) as the WSGI layer, it by default ALWAYS ensures that the Location header is absolute - thus making this attack vector mute. It is possible for application writers to modify this default behavior by setting the 'autocorrect_location_header=False`.

Severity ?

3.1 (Low)


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

CWE

CWE-601 - URL Redirection to Untrusted Site ('Open Redirect')

Assigner

GitHub_M

References

URL

Tags

	https://github.com/Flask-Middleware/flask-securit…	x_refsource_CONFIRM
	https://github.com/Flask-Middleware/flask-securit…	x_refsource_MISC

Impacted products

	Vendor	Product	Version
	Flask-Middleware	flask-security	Affected: <= 4.0.1

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-03T23:25:30.629Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_refsource_CONFIRM",
              "x_transferred"
            ],
            "url": "https://github.com/Flask-Middleware/flask-security/security/advisories/GHSA-6qmf-fj6m-686c"
          },
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://github.com/Flask-Middleware/flask-security/issues/486"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "flask-security",
          "vendor": "Flask-Middleware",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c= 4.0.1"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "The Python \"Flask-Security-Too\" package is used for adding security features to your Flask application. It is an is an independently maintained version of Flask-Security based on the 3.0.0 version of Flask-Security. All versions of Flask-Security-Too allow redirects after many successful views (e.g. /login) by honoring the ?next query param. There is code in FS to validate that the url specified in the next parameter is either relative OR has the same netloc (network location) as the requesting URL. This check utilizes Pythons urlsplit library. However many browsers are very lenient on the kind of URL they accept and \u0027fill in the blanks\u0027 when presented with a possibly incomplete URL. As a concrete example - setting http://login?next=\\\\\\github.com will pass FS\u0027s relative URL check however many browsers will gladly convert this to http://github.com. Thus an attacker could send such a link to an unwitting user, using a legitimate site and have it redirect to whatever site they want. This is considered a low severity due to the fact that if Werkzeug is used (which is very common with Flask applications) as the WSGI layer, it by default ALWAYS ensures that the Location header is absolute - thus making this attack vector mute. It is possible for application writers to modify this default behavior by setting the \u0027autocorrect_location_header=False`."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 3.1,
            "baseSeverity": "LOW",
            "confidentialityImpact": "NONE",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-601",
              "description": "CWE-601: URL Redirection to Untrusted Site (\u0027Open Redirect\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2021-05-17T18:05:10",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/Flask-Middleware/flask-security/security/advisories/GHSA-6qmf-fj6m-686c"
        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/Flask-Middleware/flask-security/issues/486"
        }
      ],
      "source": {
        "advisory": "GHSA-6qmf-fj6m-686c",
        "discovery": "UNKNOWN"
      },
      "title": "Open Redirect Vulnerability",
      "x_legacyV4Record": {
        "CVE_data_meta": {
          "ASSIGNER": "security-advisories@github.com",
          "ID": "CVE-2021-32618",
          "STATE": "PUBLIC",
          "TITLE": "Open Redirect Vulnerability"
        },
        "affects": {
          "vendor": {
            "vendor_data": [
              {
                "product": {
                  "product_data": [
                    {
                      "product_name": "flask-security",
                      "version": {
                        "version_data": [
                          {
                            "version_value": "\u003c= 4.0.1"
                          }
                        ]
                      }
                    }
                  ]
                },
                "vendor_name": "Flask-Middleware"
              }
            ]
          }
        },
        "data_format": "MITRE",
        "data_type": "CVE",
        "data_version": "4.0",
        "description": {
          "description_data": [
            {
              "lang": "eng",
              "value": "The Python \"Flask-Security-Too\" package is used for adding security features to your Flask application. It is an is an independently maintained version of Flask-Security based on the 3.0.0 version of Flask-Security. All versions of Flask-Security-Too allow redirects after many successful views (e.g. /login) by honoring the ?next query param. There is code in FS to validate that the url specified in the next parameter is either relative OR has the same netloc (network location) as the requesting URL. This check utilizes Pythons urlsplit library. However many browsers are very lenient on the kind of URL they accept and \u0027fill in the blanks\u0027 when presented with a possibly incomplete URL. As a concrete example - setting http://login?next=\\\\\\github.com will pass FS\u0027s relative URL check however many browsers will gladly convert this to http://github.com. Thus an attacker could send such a link to an unwitting user, using a legitimate site and have it redirect to whatever site they want. This is considered a low severity due to the fact that if Werkzeug is used (which is very common with Flask applications) as the WSGI layer, it by default ALWAYS ensures that the Location header is absolute - thus making this attack vector mute. It is possible for application writers to modify this default behavior by setting the \u0027autocorrect_location_header=False`."
            }
          ]
        },
        "impact": {
          "cvss": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 3.1,
            "baseSeverity": "LOW",
            "confidentialityImpact": "NONE",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N",
            "version": "3.1"
          }
        },
        "problemtype": {
          "problemtype_data": [
            {
              "description": [
                {
                  "lang": "eng",
                  "value": "CWE-601: URL Redirection to Untrusted Site (\u0027Open Redirect\u0027)"
                }
              ]
            }
          ]
        },
        "references": {
          "reference_data": [
            {
              "name": "https://github.com/Flask-Middleware/flask-security/security/advisories/GHSA-6qmf-fj6m-686c",
              "refsource": "CONFIRM",
              "url": "https://github.com/Flask-Middleware/flask-security/security/advisories/GHSA-6qmf-fj6m-686c"
            },
            {
              "name": "https://github.com/Flask-Middleware/flask-security/issues/486",
              "refsource": "MISC",
              "url": "https://github.com/Flask-Middleware/flask-security/issues/486"
            }
          ]
        },
        "source": {
          "advisory": "GHSA-6qmf-fj6m-686c",
          "discovery": "UNKNOWN"
        }
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2021-32618",
    "datePublished": "2021-05-17T18:05:11",
    "dateReserved": "2021-05-12T00:00:00",
    "dateUpdated": "2024-08-03T23:25:30.629Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1"
}

Sightings

Author	Source	Type	Date

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.

Action not permitted

GHSA-6QMF-FJ6M-686C

Impact

Patches

Workarounds

References

For more information

PYSEC-2021-123

CVE-2021-32618 (GCVE-0-2021-32618)

Tags

Sightings

Nomenclature