{"id":"CVE-2021-29621","aliases":["BIT-airflow-2021-29621","EUVD-2021-0083","GHSA-434h-p4gx-jm89","PYSEC-2021-90"],"status":"published","title":"Observable Response Discrepancy in Flask-AppBuilder","description":"Flask-AppBuilder is a development framework, built on top of Flask. User enumeration in database authentication in Flask-AppBuilder \u003c= 3.2.3. Allows for a non authenticated user to enumerate existing accounts by timing the response time from the server when you are logging in. Upgrade to version 3.3.0 or higher to resolve.","severity":{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.03404,"percentile":0.89019,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-203"],"published":"2021-05-27T18:38:36Z","modified":"2026-10-24T10:50:12Z","fixes":[{"ecosystem":"PyPI","package":"flask-appbuilder","fixed_in":["3.3.0"],"sources":["ghsa","osv"]},{"ecosystem":"Bitnami","package":"airflow","fixed_in":["1.10.1"],"sources":["osv"]}],"affected":[{"source":"ghsa","ecosystem":"PyPI","package":"flask-appbuilder","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.3.0"}]}]},{"source":"osv","ecosystem":"Bitnami","package":"airflow","ranges":[{"type":"SEMVER","events":[{"introduced":"1.10.0"},{"fixed":"1.10.1"}]}]},{"source":"osv","ecosystem":"PyPI","package":"flask-appbuilder","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.3.0"}]}],"versions":["0.1.10","0.1.11","0.1.12","0.1.13","0.1.14","0.1.15","0.1.16","0.1.17","0.1.18","0.1.19","0.1.20","0.1.21","0.1.22","0.1.23","0.1.24","0.1.25","0.1.26","0.1.27","0.1.28","0.1.29","0.1.3","0.1.33","0.1.34","0.1.35","0.1.36","0.1.37","0.1.38","0.1.4","0.1.43","0.1.44","0.1.45","0.1.46","0.1.47","0.1.5","0.1.6","0.1.7","0.1.8","0.1.9","0.10.0","0.10.1","0.10.2","0.10.3","0.10.4","0.10.5","0.10.6","0.10.7","0.2.0","0.2.1","0.2.2","0.3.0","0.3.1","0.3.10","0.3.11","0.3.12","0.3.13","0.3.14","0.3.15","0.3.16","0.3.17","0.3.2","0.3.3","0.3.4","0.3.5","0.3.6","0.3.7","0.3.8","0.3.9","0.4.0","0.4.1","0.4.2","0.4.3","0.5.0","0.5.1","0.5.2","0.5.3","0.5.4","0.5.5","0.5.6","0.6.1","0.6.10","0.6.11","0.6.12","0.6.13","0.6.14","0.6.2","0.6.3","0.6.4","0.6.5","0.6.6","0.6.7","0.6.8","0.6.9","0.7.0","0.7.1","0.7.2","0.7.3","0.7.4","0.7.5","0.7.6","0.7.7","0.7.8","0.8.0","0.8.1","0.8.2","0.8.3","0.8.4","0.8.5","0.9.0","0.9.1","0.9.2","0.9.3","1.0.0","1.0.1","1.1.0","1.1.1","1.1.2","1.1.3","1.10.0","1.11.0","1.11.1","1.12.0","1.12.1","1.12.2","1.12.3","1.12.4","1.12.5","1.13.0","1.13.1","1.2.0","1.2.1","1.3.0","1.3.1","1.3.2","1.3.3","1.3.4","1.3.5","1.3.6","1.3.7","1.4.0","1.4.1","1.4.2","1.4.3","1.4.4","1.4.5","1.4.6","1.4.7","1.5.0","1.6.0","1.6.1","1.6.2","1.6.3","1.7.0","1.7.1","1.8.0","1.8.1","1.9.0","1.9.1","1.9.2","1.9.3","1.9.4","1.9.5","1.9.6","2.0.0","2.1.0","2.1.1","2.1.10","2.1.11","2.1.12","2.1.13","2.1.2","2.1.3","2.1.4","2.1.5","2.1.6","2.1.7","2.1.8","2.1.9","2.2.0","2.2.0rc1","2.2.0rc2","2.2.1","2.2.1rc1","2.2.1rc2","2.2.1rc3","2.2.2","2.2.2rc1","2.2.2rc2","2.2.2rc3","2.2.3","2.2.3rc1","2.2.3rc2","2.2.3rc3","2.2.3rc4","2.2.3rc5","2.2.3rc6","2.2.4","2.2.4rc1","2.3.0","2.3.0rc1","2.3.0rc2","2.3.0rc3","2.3.0rc4","2.3.1","2.3.1rc1","2.3.2","2.3.2rc1","2.3.3","2.3.3rc1","2.3.3rc2","2.3.3rc3","2.3.4","2.3.4rc1","3.0.0","3.0.0rc1","3.0.0rc2","3.0.0rc3","3.0.0rc4","3.0.1","3.0.1rc1","3.1.0","3.1.0rc1","3.1.0rc2","3.1.0rc3","3.1.1","3.1.1rc1","3.1.1rc2","3.1.1rc3","3.2.0","3.2.0rc1","3.2.0rc2","3.2.1","3.2.1rc1","3.2.2","3.2.2rc1","3.2.3","3.2.3rc1","3.2.3rc2","3.3.0rc1"]},{"source":"osv","ecosystem":"PyPI","package":"flask-appbuilder","ranges":[{"type":"GIT","events":[{"introduced":"0"},{"fixed":"780bd0e8fbf2d36ada52edb769477e0a4edae580"}]},{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.3.0"}]}],"versions":["0.1.10","0.1.11","0.1.12","0.1.13","0.1.14","0.1.15","0.1.16","0.1.17","0.1.18","0.1.19","0.1.20","0.1.21","0.1.22","0.1.23","0.1.24","0.1.25","0.1.26","0.1.27","0.1.28","0.1.29","0.1.3","0.1.33","0.1.34","0.1.35","0.1.36","0.1.37","0.1.38","0.1.4","0.1.43","0.1.44","0.1.45","0.1.46","0.1.47","0.1.5","0.1.6","0.1.7","0.1.8","0.1.9","0.10.0","0.10.1","0.10.2","0.10.3","0.10.4","0.10.5","0.10.6","0.10.7","0.2.0","0.2.1","0.2.2","0.3.0","0.3.1","0.3.10","0.3.11","0.3.12","0.3.13","0.3.14","0.3.15","0.3.16","0.3.17","0.3.2","0.3.3","0.3.4","0.3.5","0.3.6","0.3.7","0.3.8","0.3.9","0.4.0","0.4.1","0.4.2","0.4.3","0.5.0","0.5.1","0.5.2","0.5.3","0.5.4","0.5.5","0.5.6","0.6.1","0.6.10","0.6.11","0.6.12","0.6.13","0.6.14","0.6.2","0.6.3","0.6.4","0.6.5","0.6.6","0.6.7","0.6.8","0.6.9","0.7.0","0.7.1","0.7.2","0.7.3","0.7.4","0.7.5","0.7.6","0.7.7","0.7.8","0.8.0","0.8.1","0.8.2","0.8.3","0.8.4","0.8.5","0.9.0","0.9.1","0.9.2","0.9.3","1.0.0","1.0.1","1.1.0","1.1.1","1.1.2","1.1.3","1.10.0","1.11.0","1.11.1","1.12.0","1.12.1","1.12.2","1.12.3","1.12.4","1.12.5","1.13.0","1.13.1","1.2.0","1.2.1","1.3.0","1.3.1","1.3.2","1.3.3","1.3.4","1.3.5","1.3.6","1.3.7","1.4.0","1.4.1","1.4.2","1.4.3","1.4.4","1.4.5","1.4.6","1.4.7","1.5.0","1.6.0","1.6.1","1.6.2","1.6.3","1.7.0","1.7.1","1.8.0","1.8.1","1.9.0","1.9.1","1.9.2","1.9.3","1.9.4","1.9.5","1.9.6","2.0.0","2.1.0","2.1.1","2.1.10","2.1.11","2.1.12","2.1.13","2.1.2","2.1.3","2.1.4","2.1.5","2.1.6","2.1.7","2.1.8","2.1.9","2.2.0","2.2.0rc1","2.2.0rc2","2.2.1","2.2.1rc1","2.2.1rc2","2.2.1rc3","2.2.2","2.2.2rc1","2.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Party Advisory","advisory","web"]},{"url":"https://github.com/dpgaspar/Flask-AppBuilder/commit/780bd0e8fbf2d36ada52edb769477e0a4edae580","tags":["x_refsource_MISC","x_transferred","Patch","Third Party Advisory","advisory","fix","web"]},{"url":"https://pypi.org/project/Flask-AppBuilder/","tags":["x_refsource_MISC","x_transferred","Product","Third Party Advisory","advisory","package"]},{"url":"https://lists.apache.org/thread.html/r5b754118ba4e996adf03863705d34168bffec202da5c6bdc9bf3add5%40%3Cannounce.apache.org%3E","tags":["mailing-list","x_refsource_MLIST","x_transferred","web"]},{"url":"https://lists.apache.org/thread.html/r466759f377651f0a690475d5a52564d0e786e82c08d5a5730a4f8352%40%3Cannounce.apache.org%3E","tags":["mailing-list","x_refsource_MLIST","x_transferred","web"]},{"url":"https://lists.apache.org/thread.html/r91067f953906d93aaa1c69fe2b5472754019cc6bd4f1ba81349d62a0%40%3Ccommits.airflow.apache.org%3E","tags":["mailing-list","x_refsource_MLIST","x_transferred","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-29621","tags":["web","advisory"]},{"url":"https://lists.apache.org/thread.html/r5b754118ba4e996adf03863705d34168bffec202da5c6bdc9bf3add5@%3Cannounce.apache.org%3E","tags":["web"]},{"url":"https://lists.apache.org/thread.html/r466759f377651f0a690475d5a52564d0e786e82c08d5a5730a4f8352@%3Cannounce.apache.org%3E","tags":["web"]},{"url":"https://lists.apache.org/thread.html/r91067f953906d93aaa1c69fe2b5472754019cc6bd4f1ba81349d62a0@%3Ccommits.airflow.apache.org%3E","tags":["web"]},{"url":"https://github.com/pypa/advisory-database/tree/main/vulns/flask-appbuilder/PYSEC-2021-90.yaml","tags":["web"]},{"url":"https://pypi.org/project/Flask-AppBuilder","tags":["web"]},{"url":"https://github.com/advisories/GHSA-434h-p4gx-jm89"},{"url":"https://github.com/dpgaspar/Flask-AppBuilder","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2021-29621","title":"Observable Response Discrepancy in Flask-AppBuilder","description":"Flask-AppBuilder is a development framework, built on top of Flask. User enumeration in database authentication in Flask-AppBuilder \u003c= 3.2.3. Allows for a non authenticated user to enumerate existing accounts by timing the response time from the server when you are logging in. Upgrade to version 3.3.0 or higher to resolve.","status":"published","published":"2021-06-07T19:00:12Z","modified":"2024-08-03T22:11:06.246Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-203"],"updated_at":"2026-11-02T14:33:06.658806Z"}],"euvd":[{"id":"EUVD-2021-0083","description":"Flask-AppBuilder is a development framework, built on top of Flask. User enumeration in database authentication in Flask-AppBuilder \u003c= 3.2.3. Allows for a non authenticated user to enumerate existing accounts by timing the response time from the server when you are logging in. Upgrade to version 3.3.0 or higher to resolve.","status":"published","published":"2021-06-07T19:00:12Z","modified":"2024-08-03T22:11:06Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","level":"medium"}],"updated_at":"2026-11-03T03:24:44.540278Z"}],"ghsa":[{"id":"GHSA-434h-p4gx-jm89","title":"Observable Response Discrepancy in Flask-AppBuilder","description":"### Impact\nUser enumeration in database authentication in Flask-AppBuilder \u003c= 3.2.3. Allows for a non authenticated user to enumerate existing accounts by timing the response time from the server when you are logging in.\n\n### Patches\nUpgrade to 3.3.0\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Open an issue in [Flask-AppBuilder](https://github.com/dpgaspar/Flask-AppBuilder)","status":"published","published":"2021-05-27T18:38:36Z","modified":"2025-03-07T19:08:59Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","level":"medium"},{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","level":"medium"}],"cwes":["CWE-203"],"updated_at":"2026-11-02T14:38:34.185137Z"}],"nvd":[{"id":"CVE-2021-29621","description":"Flask-AppBuilder is a development framework, built on top of Flask. User enumeration in database authentication in Flask-AppBuilder \u003c= 3.2.3. Allows for a non authenticated user to enumerate existing accounts by timing the response time from the server when you are logging in. Upgrade to version 3.3.0 or higher to resolve.","status":"published","published":"2021-06-07T19:15:07.6Z","modified":"2026-06-17T03:48:02.597Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","level":"medium","assessor":"secondary"},{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","level":"medium","assessor":"primary"},{"version":"2.0","score":5,"vector":"AV:N/AC:L/Au:N/C:P/I:N/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-203"],"updated_at":"2026-11-02T14:06:54.439974Z"}],"osv":[{"id":"CVE-2021-29621","description":"Flask-AppBuilder is a development framework, built on top of Flask. User enumeration in database authentication in Flask-AppBuilder \u003c= 3.2.3. Allows for a non authenticated user to enumerate existing accounts by timing the response time from the server when you are logging in. Upgrade to version 3.3.0 or higher to resolve.","status":"published","published":"2021-06-07T19:15:07.6Z","modified":"2026-10-24T10:50:12.433922664Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","level":"medium"}],"updated_at":"2026-11-02T15:44:19.483607Z"},{"id":"GHSA-434h-p4gx-jm89","title":"Observable Response Discrepancy in Flask-AppBuilder","description":"### Impact\nUser enumeration in database authentication in Flask-AppBuilder \u003c= 3.2.3. Allows for a non authenticated user to enumerate existing accounts by timing the response time from the server when you are logging in.\n\n### Patches\nUpgrade to 3.3.0\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Open an issue in [Flask-AppBuilder](https://github.com/dpgaspar/Flask-AppBuilder)","status":"published","published":"2021-05-27T18:38:36Z","modified":"2026-07-08T06:27:56.529823809Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","level":"medium"},{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-203"],"updated_at":"2026-11-02T15:46:36.434231Z"},{"id":"BIT-airflow-2021-29621","title":"Observable Response Discrepancy in Flask-AppBuilder","description":"Flask-AppBuilder is a development framework, built on top of Flask. User enumeration in database authentication in Flask-AppBuilder \u003c= 3.2.3. Allows for a non authenticated user to enumerate existing accounts by timing the response time from the server when you are logging in. Upgrade to version 3.3.0 or higher to resolve.","status":"published","published":"2024-03-06T10:59:16.077Z","modified":"2026-09-08T08:45:19.16837607Z","updated_at":"2026-11-02T15:28:28.267217Z"},{"id":"PYSEC-2021-90","description":"Flask-AppBuilder is a development framework, built on top of Flask. User enumeration in database authentication in Flask-AppBuilder \u003c= 3.2.3. Allows for a non authenticated user to enumerate existing accounts by timing the response time from the server when you are logging in. Upgrade to version 3.3.0 or higher to resolve.","status":"published","published":"2021-06-07T19:15:00Z","modified":"2023-12-06T01:01:09.861844Z","updated_at":"2026-11-02T15:52:53.449407Z"}]}}