CVE-2021-3563

Exp

A flaw was found in openstack-keystone. Only the first 72 characters of an application secret are verified allowing attackers bypass some password complexity which administrators may be counting on. The highest threat from this vulnerability is to data confidentiality and integrity.

Published: 2022-08-26 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2021-3563 is rated High Exploit Risk (68.9/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.27%). Core evidence: 3 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +1.23% over the last day, indicating growing attacker interest. Mandatory action: Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2021-3563

EDB-ID Source Kind Published Link
nvd_ref exploit_tag Exploit-DB ↗
nvd_ref exploit_tag Exploit-DB ↗
nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2021-3563

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.04% 1.27% +1.23%
2 2026-05-09 0.05% 0.04% -0.01%
3 2026-02-04 0.05%

Full EPSS history (20 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-3563

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.4 3.1 HIGH
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
2.2 5.2 [email protected]

Weakness enumeration for CVE-2021-3563

GitHub Security Advisory for CVE-2021-3563

GHSA-cc99-whm5-mmq3 · Severity: critical · Ecosystem: pip — Openstack Keystone Incorrect Authorization vulnerability

OS Trackers for CVE-2021-3563

vendor priority summary link
debian not yet assigned CVE-2021-3563 not yet assigned priority: Debian including 1 source packages (keystone), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 3, open 2. https://security-tracker.debian.org/tracker/CVE-2021-3563
redhat medium https://access.redhat.com/security/cve/CVE-2021-3563
suse high https://www.suse.com/security/cve/CVE-2021-3563/
ubuntu low CVE-2021-3563 low priority: Ubuntu including 1 source packages (keystone), 16 status rows across 16 suites (bionic, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): ignored 7, needed 3, not-affected 3, DNE 1, needs-triage 1, released 1. https://ubuntu.com/security/CVE-2021-3563

Affected software / configurations for CVE-2021-3563

Vendor Product Version Raw CPE
openstack keystone cpe:2.3:a:openstack:keystone:*:*:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
debian debian_linux 11.0 cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*
redhat openstack_platform 10.0 cpe:2.3:a:redhat:openstack_platform:10.0:*:*:*:*:*:*:*
redhat openstack_platform 13.0 cpe:2.3:a:redhat:openstack_platform:13.0:*:*:*:*:*:*:*
redhat openstack_platform 16.1 cpe:2.3:a:redhat:openstack_platform:16.1:*:*:*:*:*:*:*
redhat openstack_platform 16.2 cpe:2.3:a:redhat:openstack_platform:16.2:*:*:*:*:*:*:*

References for CVE-2021-3563

URL Tags
https://access.redhat.com/security/cve/CVE-2021-3563 Issue Tracking Third Party Advisory
https://bugs.launchpad.net/ossa/+bug/1901891 Exploit Issue Tracking Third Party Advisory VDB Entry
https://bugzilla.redhat.com/show_bug.cgi?id=1962908 Exploit Issue Tracking Third Party Advisory Vendor Advisory
https://lists.debian.org/debian-lts-announce/2024/01/msg00007.html
https://security-tracker.debian.org/tracker/CVE-2021-3563 Exploit Issue Tracking Third Party Advisory
cvelogic Threat Intelligence