{"id":"CVE-2021-29621","aliases":["GHSA-434h-p4gx-jm89","BIT-airflow-2021-29621","PYSEC-2021-90"],"title":"Observable Response Discrepancy in Flask-AppBuilder","summary":"Observable Response Discrepancy in Flask-AppBuilder","severity":"medium","cvss":5.3,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","vendor":"flask-appbuilder","product":"flask-appbuilder","ecosystem":"pip","affected":["flask-appbuilder < 3.3.0"],"patched":["flask-appbuilder 3.3.0"],"published":"2021-05-27","updated":"2026-07-08","source":"OSV","sourceUrl":"https://osv.dev/vulnerability/GHSA-434h-p4gx-jm89","references":[{"url":"https://github.com/dpgaspar/Flask-AppBuilder/security/advisories/GHSA-434h-p4gx-jm89"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-29621"},{"url":"https://github.com/dpgaspar/Flask-AppBuilder/commit/780bd0e8fbf2d36ada52edb769477e0a4edae580"},{"url":"https://github.com/dpgaspar/Flask-AppBuilder"},{"url":"https://github.com/pypa/advisory-database/tree/main/vulns/flask-appbuilder/PYSEC-2021-90.yaml"},{"url":"https://lists.apache.org/thread.html/r466759f377651f0a690475d5a52564d0e786e82c08d5a5730a4f8352%40%3Cannounce.apache.org%3E"},{"url":"https://lists.apache.org/thread.html/r466759f377651f0a690475d5a52564d0e786e82c08d5a5730a4f8352@%3Cannounce.apache.org%3E"},{"url":"https://lists.apache.org/thread.html/r5b754118ba4e996adf03863705d34168bffec202da5c6bdc9bf3add5%40%3Cannounce.apache.org%3E"},{"url":"https://lists.apache.org/thread.html/r5b754118ba4e996adf03863705d34168bffec202da5c6bdc9bf3add5@%3Cannounce.apache.org%3E"},{"url":"https://lists.apache.org/thread.html/r91067f953906d93aaa1c69fe2b5472754019cc6bd4f1ba81349d62a0%40%3Ccommits.airflow.apache.org%3E"},{"url":"https://lists.apache.org/thread.html/r91067f953906d93aaa1c69fe2b5472754019cc6bd4f1ba81349d62a0@%3Ccommits.airflow.apache.org%3E"},{"url":"https://pypi.org/project/Flask-AppBuilder"}],"tags":["osv","pip"],"epss":0.03404,"epssPercentile":0.88343,"ingestedAt":"2026-07-08T18:25:45.230Z","slug":"CVE-2021-29621","body":"## Overview\n\n### Impact\nUser enumeration in database authentication in Flask-AppBuilder <= 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)\n\n## Affected packages\n\n- `flask-appbuilder < 3.3.0`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `flask-appbuilder 3.3.0`","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":29.2,"likelihood":0.7,"exploitation":0,"ransomware":0},"changes":[]}