CVE-2021-21673

MEDIUMNVD 6.16.1—

6.1

Jenkins CAS Plugin 1.6.0 and earlier improperly determines that a redirect URL after login is legitimately pointing to Jenkins, allowing attackers to perform phishing attacks.

CVSS v3: 6.1
EG Score: 6.1(medium)
EPSS: 23.0%
KEV: Not listed

Published

June 30, 2021

Last Modified

November 21, 2024

References (4)

jenkinsci-cert@googlegroupshttp://www.openwall.com/lists/oss-security/2021/06/30/1
jenkinsci-cert@googlegroupshttps://www.jenkins.io/security/advisory/2021-06-30/#SECURITY-2387
af854a3a-2127-422b-91ae-364da2661108http://www.openwall.com/lists/oss-security/2021/06/30/1
af854a3a-2127-422b-91ae-364da2661108https://www.jenkins.io/security/advisory/2021-06-30/#SECURITY-2387

Affected Packages

(1 across 1 ecosystem)

Maven(1)

Package	Vulnerable range	Fixed in	Dependents
org.jenkins-ci.plugins:cas-plugin	1.0.0 ... 1.6.0 (12 versions)	1.6.1	—

Data Freshness Timeline

(refreshed 9× in last 7d / 17× in last 30d)

Every time one of our enrichment pipelines (NVD, MITRE cvelistV5, EPSS, CISA KEV, GHSA, OSV, vendor advisories) ran against this CVE. Most recent first.

2026-06-02 20:11 UTCepss_batch
2026-06-02 20:11 UTCepss_batch
2026-06-01 13:50 UTCepss_batch
2026-06-01 13:50 UTCepss_batch
2026-05-31 22:29 UTCepss_batch
2026-05-31 22:29 UTCepss_batch
2026-05-29 13:42 UTCepss_batch
2026-05-28 13:43 UTCepss_batch
2026-05-28 13:43 UTCepss_batch
2026-05-27 13:39 UTCepss_batch
2026-05-26 14:16 UTCEG score recompute
2026-05-26 13:42 UTCepss_batch
2026-05-26 13:42 UTCepss_batch
2026-05-26 07:17 UTCepss_batch
2026-05-26 07:17 UTCepss_batch
2026-05-24 16:49 UTCepss_batch
2026-05-23 23:05 UTCOSV refresh

Frequently asked(5)

What is CVE-2021-21673?

CVE-2021-21673 is a medium vulnerability published on June 30, 2021. Jenkins CAS Plugin 1.6.0 and earlier improperly determines that a redirect URL after login is legitimately pointing to Jenkins, allowing attackers to perform phishing attacks.

When was CVE-2021-21673 disclosed?

CVE-2021-21673 was first published in the National Vulnerability Database on June 30, 2021, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2021-21673 actively exploited?

CVE-2021-21673 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 23.0% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2021-21673?

CVE-2021-21673 has a CVSS v3 base score of 6.1 (NVD).

How do I remediate CVE-2021-21673?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-21673, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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CVE-2021-21673

📅 Published

🔄 Last Modified

🔗 References (4)