Auth bypass in Red Hat Keycloak
CVE-2020-27838
A flaw was found in keycloak in versions prior to 13.0.0. The client registration endpoint allows fetching information about PUBLIC clients (like client secret) without authentication which could be an issue if the same PUBLIC client changed to CONFIDENTIAL later. The highest threat from this vulnerability is to data confidentiality.
Vulnerability class: Broken Authentication
EPSS: 0.179 (96.9th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N.
Affected products
- Redhat Keycloak
- Redhat Single_sign-on — versions 7.0
- N/a Keycloak — versions keycloak 13.0.0
Weakness classification (CWE)
Public proof-of-concept exploits
References
- secalert@redhat.com (x_refsource_MISC, Issue Tracking, Vendor Advisory)
Frequently asked questions
- What is CVE-2020-27838?
- CVE-2020-27838 is a medium-severity vulnerability in Red Hat Keycloak, classified under Improper Authentication. CVSS score: 6.5/10. Published 2021-03-08.
- How severe is CVE-2020-27838?
- Medium severity. CVSS v3 base score is 6.5 out of 10.
- Is CVE-2020-27838 known to be exploited?
- 4 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.