{"cve":"CVE-2021-38155","nvd":{"published":"2021-08-06T21:15:06.687","modified":"2026-06-17T04:01:35.487","status":"Modified","description":"OpenStack Keystone 10.x through 16.x before 16.0.2, 17.x before 17.0.1, 18.x before 18.0.1, and 19.x before 19.0.1 allows information disclosure during account locking (related to PCI DSS features). By guessing the name of an account and failing to authenticate multiple times, any unauthenticated actor could both confirm the account exists and obtain that account's corresponding UUID, which might be leveraged for other unrelated attacks. All deployments enabling security_compliance.lockout_failure_attempts are affected.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","score":7.5},"cwes":["CWE-307"],"references":["http://www.openwall.com/lists/oss-security/2021/08/10/5","https://launchpad.net/bugs/1688137","https://lists.debian.org/debian-lts-announce/2024/01/msg00007.html","https://security.openstack.org/ossa/OSSA-2021-003.html","http://www.openwall.com/lists/oss-security/2021/08/10/5"],"products":["openstack:keystone"],"source":"nvd","synced_at":"2026-10-19T21:21:13.713336758+00:00"},"epss":{"cve":"CVE-2021-38155","score":0.02478,"percentile":0.84565,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-4225-97pr-rr52","url":"https://osv.dev/vulnerability/GHSA-4225-97pr-rr52","summary":"OpenStack Keystone allows information disclosure during account locking","modified":"2026-07-07T11:56:21.033449617Z","packages":[{"ecosystem":"PyPI","name":"keystone","purl":"pkg:pypi/keystone","ranges":[">=10.0 <16.0.2"],"fixed":["16.0.2"]},{"ecosystem":"PyPI","name":"keystone","purl":"pkg:pypi/keystone","ranges":[">=17.0 <17.0.1"],"fixed":["17.0.1"]},{"ecosystem":"PyPI","name":"keystone","purl":"pkg:pypi/keystone","ranges":[">=18.0 <18.0.1"],"fixed":["18.0.1"]},{"ecosystem":"PyPI","name":"keystone","purl":"pkg:pypi/keystone","ranges":[">=19.0 <19.0.1"],"fixed":["19.0.1"]}]},{"id":"PYSEC-2026-830","url":"https://osv.dev/vulnerability/PYSEC-2026-830","summary":"OpenStack Keystone allows information disclosure during account locking","modified":"2026-07-07T11:45:41.977390817Z","packages":[{"ecosystem":"PyPI","name":"keystone","purl":"pkg:pypi/keystone","ranges":[">=10.0 <16.0.2",">=17.0 <17.0.1",">=18.0 <18.0.1",">=19.0 <19.0.1"],"fixed":["16.0.2","17.0.1","18.0.1","19.0.1"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}