What is CVE-2021-21603?

CVE-2021-21603 is a medium-severity vulnerability in Jenkins, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2021-01-13.

How severe is CVE-2021-21603?

Medium severity. CVSS v3 base score is 5.4 out of 10.

XSS in Jenkins

CVE-2021-21603

Jenkins 2.274 and earlier, LTS 2.263.1 and earlier does not escape notification bar response contents, resulting in a cross-site scripting (XSS) vulnerability.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.010 (60.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.

Affected products

Jenkins
Jenkins Project — versions unspecified

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

jenkinsci-cert@googlegroups.com (x_refsource_CONFIRM, Vendor Advisory)

Frequently asked questions

What is CVE-2021-21603?: CVE-2021-21603 is a medium-severity vulnerability in Jenkins, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2021-01-13.
How severe is CVE-2021-21603?: Medium severity. CVSS v3 base score is 5.4 out of 10.