{"api_version":"1","generated_at":"2026-07-24T23:43:45+00:00","cve":"CVE-2021-23393","urls":{"html":"https://cve.report/CVE-2021-23393","api":"https://cve.report/api/cve/CVE-2021-23393.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2021-23393","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-23393"},"summary":{"title":"CVE-2021-23393","description":"This affects the package Flask-Unchained before 0.9.0. When using the the _validate_redirect_url function, it is possible to bypass URL validation and redirect a user to an arbitrary URL by providing multiple back slashes such as \\\\\\evil.com/path. 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This vulnerability is only exploitable if an alternative WSGI server other than Werkzeug is used, or the default behaviour of Werkzeug is modified using 'autocorrect_location_header=False."}]},"impact":{"cvss":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N/E:P/RL:U/RC:C","baseScore":5.4,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"REQUIRED","scope":"UNCHANGED","confidentialityImpact":"LOW","integrityImpact":"LOW","availabilityImpact":"NONE"}},"credit":[{"lang":"eng","value":"Noam Moshe of Claroty"}]},"nvd":{"publishedDate":"2021-06-11 00:15:00","lastModifiedDate":"2021-06-22 16:53:00","problem_types":["CWE-601"],"metrics":{"baseMetricV3":{"cvssV3":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"REQUIRED","scope":"UNCHANGED","confidentialityImpact":"LOW","integrityImpact":"LOW","availabilityImpact":"NONE","baseScore":5.4,"baseSeverity":"MEDIUM"},"exploitabilityScore":2.8,"impactScore":2.5},"baseMetricV2":{"cvssV2":{"version":"2.0","vectorString":"AV:N/AC:M/Au:N/C:P/I:P/A:N","accessVector":"NETWORK","accessComplexity":"MEDIUM","authentication":"NONE","confidentialityImpact":"PARTIAL","integrityImpact":"PARTIAL","availabilityImpact":"NONE","baseScore":5.8},"severity":"MEDIUM","exploitabilityScore":8.6,"impactScore":4.9,"acInsufInfo":false,"obtainAllPrivilege":false,"obtainUserPrivilege":false,"obtainOtherPrivilege":false,"userInteractionRequired":true}},"configurations":{"CVE_data_version":"4.0","nodes":[{"operator":"OR","children":[],"cpe_match":[{"vulnerable":true,"cpe23Uri":"cpe:2.3:a:flask_unchained_project:flask_unchained:*:*:*:*:*:*:*:*","versionEndExcluding":"0.9.0","cpe_name":[]}]}]}},"legacy_mitre":{"record":{"CveYear":"2021","CveId":"23393","Ordinal":"198120","Title":"CVE-2021-23393","CVE":"CVE-2021-23393","Year":"2021"},"notes":[{"CveYear":"2021","CveId":"23393","Ordinal":"1","NoteData":"This affects the package Flask-Unchained before 0.9.0. 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