{"id":"CVE-2020-15240","aliases":["EUVD-2020-1445","GHSA-58r4-h6v8-jcvm"],"status":"published","title":"Regression in JWT Signature Validation","description":"omniauth-auth0 (rubygems) versions \u003e= 2.3.0 and \u003c 2.4.1 improperly validate the JWT token signature when using the `jwt_validator.verify` method. Improper validation of the JWT token signature can allow an attacker to bypass authentication and authorization. You are affected by this vulnerability if all of the following conditions apply: 1. You are using `omniauth-auth0`. 2. You are using `JWTValidator.verify` method directly OR you are not authenticating using the SDK’s default Authorization Code Flow. The issue is patched in version 2.4.1.","severity":{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00803,"percentile":0.57137,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-287","CWE-347"],"published":"2020-10-21T17:25:14Z","modified":"2026-10-20T10:51:54Z","fixes":[{"ecosystem":"RubyGems","package":"omniauth-auth0","fixed_in":["2.4.1"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"RubyGems","package":"omniauth-auth0","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.3.0"},{"fixed":"2.4.1"}]}]},{"source":"osv","ecosystem":"RubyGems","package":"omniauth-auth0","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.3.0"},{"fixed":"2.4.1"}]}],"versions":["2.3.0","2.3.1","2.4.0"]}],"products":[{"vendor":"auth0","product":"omniauth-auth0"}],"references":[{"url":"https://github.com/auth0/omniauth-auth0/security/advisories/GHSA-58r4-h6v8-jcvm","tags":["x_refsource_CONFIRM","x_transferred","Third Party Advisory","advisory","web"]},{"url":"https://github.com/auth0/omniauth-auth0/commit/fd3a14f4ccdfbc515d1121d6378ff88bf55a7a7a","tags":["x_refsource_MISC","x_transferred","Patch","Third Party Advisory","fix","web"]},{"url":"https://rubygems.org/gems/omniauth-auth0","tags":["x_refsource_MISC","x_transferred","Product","Vendor Advisory","advisory","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2020-15240","tags":["advisory"]},{"url":"https://github.com/rubysec/ruby-advisory-db/blob/master/gems/omniauth-auth0/CVE-2020-15240.yml","tags":["web"]},{"url":"https://github.com/advisories/GHSA-58r4-h6v8-jcvm"},{"url":"https://github.com/auth0/omniauth-auth0","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2020-15240","title":"Regression in JWT Signature Validation","description":"omniauth-auth0 (rubygems) versions \u003e= 2.3.0 and \u003c 2.4.1 improperly validate the JWT token signature when using the `jwt_validator.verify` method. Improper validation of the JWT token signature can allow an attacker to bypass authentication and authorization. You are affected by this vulnerability if all of the following conditions apply: 1. You are using `omniauth-auth0`. 2. You are using `JWTValidator.verify` method directly OR you are not authenticating using the SDK’s default Authorization Code Flow. The issue is patched in version 2.4.1.","status":"published","published":"2020-10-21T17:25:14Z","modified":"2024-08-04T13:08:22.896Z","cvss":[{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"high","assessor":"cna"}],"cwes":["CWE-287","CWE-347"],"updated_at":"2026-11-02T14:35:50.228781Z"}],"euvd":[{"id":"EUVD-2020-1445","description":"omniauth-auth0 (rubygems) versions \u003e= 2.3.0 and \u003c 2.4.1 improperly validate the JWT token signature when using the `jwt_validator.verify` method. Improper validation of the JWT token signature can allow an attacker to bypass authentication and authorization. You are affected by this vulnerability if all of the following conditions apply: 1. You are using `omniauth-auth0`. 2. You are using `JWTValidator.verify` method directly OR you are not authenticating using the SDK’s default Authorization Code Flow. The issue is patched in version 2.4.1.","status":"published","published":"2020-10-21T17:25:14Z","modified":"2024-08-04T13:08:22Z","cvss":[{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"high"}],"updated_at":"2026-11-03T03:07:32.55679Z"}],"ghsa":[{"id":"GHSA-58r4-h6v8-jcvm","title":"Regression in JWT Signature Validation","description":"### Overview\nVersions after and including `2.3.0` are improperly validating the JWT token signature when using the `JWTValidator.verify` method.  Improper validation of the JWT token signature when not using the default Authorization Code Flow can allow an attacker to bypass authentication and authorization.\n\n### Am I affected?\nYou are affected by this vulnerability if all of the following conditions apply:\n\n- You are using `omniauth-auth0`.\n- You are using `JWTValidator.verify` method directly OR you are not authenticating using the SDK’s default Authorization Code Flow.\n\n### How to fix that?\nUpgrade to version `2.4.1`.\n\n### Will this update impact my users?\nThe fix provided in this version will not affect your users.","status":"published","published":"2020-11-03T02:31:38Z","modified":"2023-05-04T19:55:01Z","cvss":[{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"high"}],"cwes":["CWE-287","CWE-347"],"updated_at":"2026-11-02T14:36:52.310293Z"}],"nvd":[{"id":"CVE-2020-15240","description":"omniauth-auth0 (rubygems) versions \u003e= 2.3.0 and \u003c 2.4.1 improperly validate the JWT token signature when using the `jwt_validator.verify` method. Improper validation of the JWT token signature can allow an attacker to bypass authentication and authorization. You are affected by this vulnerability if all of the following conditions apply: 1. You are using `omniauth-auth0`. 2. You are using `JWTValidator.verify` method directly OR you are not authenticating using the SDK’s default Authorization Code Flow. The issue is patched in version 2.4.1.","status":"published","published":"2020-10-21T18:15:12.813Z","modified":"2026-06-17T02:56:20.36Z","cvss":[{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"high","assessor":"secondary"},{"version":"3.1","score":9.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"critical","assessor":"primary"},{"version":"2.0","score":5.8,"vector":"AV:N/AC:M/Au:N/C:P/I:P/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-287","CWE-347"],"updated_at":"2026-11-02T14:06:20.704992Z"}],"osv":[{"id":"CVE-2020-15240","description":"omniauth-auth0 (rubygems) versions \u003e= 2.3.0 and \u003c 2.4.1 improperly validate the JWT token signature when using the `jwt_validator.verify` method. Improper validation of the JWT token signature can allow an attacker to bypass authentication and authorization. You are affected by this vulnerability if all of the following conditions apply: 1. You are using `omniauth-auth0`. 2. You are using `JWTValidator.verify` method directly OR you are not authenticating using the SDK’s default Authorization Code Flow. The issue is patched in version 2.4.1.","status":"published","published":"2020-10-21T18:15:12.813Z","modified":"2026-10-20T10:51:54.008553126Z","cvss":[{"version":"3.1","score":9.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"critical"}],"updated_at":"2026-11-02T15:44:14.828228Z"},{"id":"GHSA-58r4-h6v8-jcvm","title":"Regression in JWT Signature Validation","description":"### Overview\nVersions after and including `2.3.0` are improperly validating the JWT token signature when using the `JWTValidator.verify` method.  Improper validation of the JWT token signature when not using the default Authorization Code Flow can allow an attacker to bypass authentication and authorization.\n\n### Am I affected?\nYou are affected by this vulnerability if all of the following conditions apply:\n\n- You are using `omniauth-auth0`.\n- You are using `JWTValidator.verify` method directly OR you are not authenticating using the SDK’s default Authorization Code Flow.\n\n### How to fix that?\nUpgrade to version `2.4.1`.\n\n### Will this update impact my users?\nThe fix provided in this version will not affect your users.","status":"published","published":"2020-11-03T02:31:38Z","modified":"2026-07-08T05:59:47.963127968Z","cvss":[{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"high"}],"cwes":["CWE-287","CWE-347"],"updated_at":"2026-11-02T15:46:38.213481Z"}]}}