{"id":"CVE-2021-41194","state":"PUBLISHED","title":"Improper Access Control in jupyterhub-firstuseauthenticator","description":"FirstUseAuthenticator is a JupyterHub authenticator that helps new users set their password on their first login to JupyterHub. When JupyterHub is used with FirstUseAuthenticator, a vulnerability in versions prior to 1.0.0 allows unauthorized access to any user's account if `create_users=True` and the username is known or guessed. One may upgrade to version 1.0.0 or apply a patch manually to mitigate the vulnerability. For those who cannot upgrade, there is no complete workaround, but a partial mitigation exists. One can disable user creation with `c.FirstUseAuthenticator.create_users = False`, which will only allow login with fully normalized usernames for already existing users prior to jupyterhub-firstuserauthenticator 1.0.0. If any users have never logged in with their normalized username (i.e. lowercase), they will still be vulnerable until a patch or upgrade occurs.","publishedAt":"2021-10-28T19:40:12.000Z","updatedAt":"2024-08-04T03:08:31.328Z","severity":{"score":9.1,"label":"Critical","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["jupyterhub firstuseauthenticator"],"affected":[{"vendor":"jupyterhub","product":"firstuseauthenticator","versions":[{"version":"< 1.0.0","status":"affected"}]}],"references":["https://github.com/jupyterhub/firstuseauthenticator/security/advisories/GHSA-5xvc-vgmp-jgc3","https://github.com/jupyterhub/firstuseauthenticator/pull/38","https://github.com/jupyterhub/firstuseauthenticator/pull/38.patch"],"weaknesses":["CWE-284"],"ingestedAt":"2026-10-29T19:49:01.697Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2021/41xxx/CVE-2021-41194.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.1","cveMetadata":{"cveId":"CVE-2021-41194","state":"PUBLISHED","datePublished":"2021-10-28T19:40:12.000Z","dateUpdated":"2024-08-04T03:08:31.328Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2021-09-15T00:00:00.000Z"},"containers":{"cna":{"title":"Improper Access Control in jupyterhub-firstuseauthenticator","descriptions":[{"lang":"en","value":"FirstUseAuthenticator is a JupyterHub authenticator that helps new users set their password on their first login to JupyterHub. When JupyterHub is used with FirstUseAuthenticator, a vulnerability in versions prior to 1.0.0 allows unauthorized access to any user's account if `create_users=True` and the username is known or guessed. One may upgrade to version 1.0.0 or apply a patch manually to mitigate the vulnerability. For those who cannot upgrade, there is no complete workaround, but a partial mitigation exists. One can disable user creation with `c.FirstUseAuthenticator.create_users = False`, which will only allow login with fully normalized usernames for already existing users prior to jupyterhub-firstuserauthenticator 1.0.0. If any users have never logged in with their normalized username (i.e. lowercase), they will still be vulnerable until a patch or upgrade occurs."}],"affected":[{"vendor":"jupyterhub","product":"firstuseauthenticator","versions":[{"version":"< 1.0.0","status":"affected"}]}],"references":[{"url":"https://github.com/jupyterhub/firstuseauthenticator/security/advisories/GHSA-5xvc-vgmp-jgc3","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/jupyterhub/firstuseauthenticator/pull/38","tags":["x_refsource_MISC"]},{"url":"https://github.com/jupyterhub/firstuseauthenticator/pull/38.patch","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":9.1,"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:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-284","description":"CWE-284: Improper Access Control","lang":"en","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","dateUpdated":"2021-10-28T19:40:11.000Z","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa"},"source":{"advisory":"GHSA-5xvc-vgmp-jgc3","discovery":"UNKNOWN"},"x_legacyV4Record":{"CVE_data_meta":{"ASSIGNER":"security-advisories@github.com","ID":"CVE-2021-41194","STATE":"PUBLIC","TITLE":"Improper Access Control in jupyterhub-firstuseauthenticator"},"affects":{"vendor":{"vendor_data":[{"product":{"product_data":[{"product_name":"firstuseauthenticator","version":{"version_data":[{"version_value":"< 1.0.0"}]}}]},"vendor_name":"jupyterhub"}]}},"data_format":"MITRE","data_type":"CVE","data_version":"4.0","description":{"description_data":[{"lang":"eng","value":"FirstUseAuthenticator is a JupyterHub authenticator that helps new users set their password on their first login to JupyterHub. When JupyterHub is used with FirstUseAuthenticator, a vulnerability in versions prior to 1.0.0 allows unauthorized access to any user's account if `create_users=True` and the username is known or guessed. One may upgrade to version 1.0.0 or apply a patch manually to mitigate the vulnerability. For those who cannot upgrade, there is no complete workaround, but a partial mitigation exists. One can disable user creation with `c.FirstUseAuthenticator.create_users = False`, which will only allow login with fully normalized usernames for already existing users prior to jupyterhub-firstuserauthenticator 1.0.0. If any users have never logged in with their normalized username (i.e. lowercase), they will still be vulnerable until a patch or upgrade occurs."}]},"impact":{"cvss":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":9.1,"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:N","version":"3.1"}},"problemtype":{"problemtype_data":[{"description":[{"lang":"eng","value":"CWE-284: Improper Access Control"}]}]},"references":{"reference_data":[{"name":"https://github.com/jupyterhub/firstuseauthenticator/security/advisories/GHSA-5xvc-vgmp-jgc3","refsource":"CONFIRM","url":"https://github.com/jupyterhub/firstuseauthenticator/security/advisories/GHSA-5xvc-vgmp-jgc3"},{"name":"https://github.com/jupyterhub/firstuseauthenticator/pull/38","refsource":"MISC","url":"https://github.com/jupyterhub/firstuseauthenticator/pull/38"},{"name":"https://github.com/jupyterhub/firstuseauthenticator/pull/38.patch","refsource":"MISC","url":"https://github.com/jupyterhub/firstuseauthenticator/pull/38.patch"}]},"source":{"advisory":"GHSA-5xvc-vgmp-jgc3","discovery":"UNKNOWN"}}},"adp":[{"title":"CVE Program Container","references":[{"url":"https://github.com/jupyterhub/firstuseauthenticator/security/advisories/GHSA-5xvc-vgmp-jgc3","tags":["x_refsource_CONFIRM","x_transferred"]},{"url":"https://github.com/jupyterhub/firstuseauthenticator/pull/38","tags":["x_refsource_MISC","x_transferred"]},{"url":"https://github.com/jupyterhub/firstuseauthenticator/pull/38.patch","tags":["x_refsource_MISC","x_transferred"]}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2024-08-04T03:08:31.328Z"}}]}}}