CVE-2021-38155

Name: CVE-2021-38155
Creator: NVD / NIST
Published: 2021-08-06T21:15:06.687+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 2.46%

Last modified Jun 17, 2026

CVE-2021-38155 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. 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. EPSS estimates a 2.46% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS Probability

2.46%

82.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-307

Affected Software

Vendor	Product	Versions
Openstack	Keystone	>= 10.0.0, < 16.0.2
Openstack	Keystone	>= 17.0.0, < 17.0.1
Openstack	Keystone	>= 18.0.0, < 18.0.1
Openstack	Keystone	>= 19.0.0, < 19.0.1

References

http://www.openwall.com/lists/oss-security/2021/08/10/5Mailing List, Patch, Third Party Advisory
https://launchpad.net/bugs/1688137Exploit, Issue Tracking, Patch, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2024/01/msg00007.html
https://security.openstack.org/ossa/OSSA-2021-003.htmlPatch, Vendor Advisory
http://www.openwall.com/lists/oss-security/2021/08/10/5Mailing List, Patch, Third Party Advisory
https://launchpad.net/bugs/1688137Exploit, Issue Tracking, Patch, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2024/01/msg00007.html
https://security.openstack.org/ossa/OSSA-2021-003.htmlPatch, Vendor Advisory

Timeline

Published: Aug 6, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-38155?

How severe is CVE-2021-38155?

CVE-2021-38155 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 2.46% probability of exploitation in the next 30 days.

How do I fix CVE-2021-38155?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-38155?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST