CVE-2021-20829

Name: CVE-2021-20829
Creator: NVD / NIST
Published: 2021-09-21T10:15:07.543+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.1/10EPSS 0.73%

Last modified Jun 17, 2026

CVE-2021-20829 is a medium-severity vulnerability rated 6.1/10 on the CVSS scale. Cross-site scripting vulnerability due to the inadequate tag sanitization in GROWI versions v4.2.19 and earlier allows remote attackers to execute an arbitrary script on the web browser of the user who accesses a specially crafted page.. EPSS estimates a 0.73% chance of exploitation in the next 30 days.

Description

Cross-site scripting vulnerability due to the inadequate tag sanitization in GROWI versions v4.2.19 and earlier allows remote attackers to execute an arbitrary script on the web browser of the user who accesses a specially crafted page.

Metrics

CVSS 3.1

6.1/10

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

EPSS Probability

0.73%

49.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

Affected Software

Vendor	Product	Versions
Weseek	Growi	<= 4.2.19

References

https://jvn.jp/en/vu/JVNVU94889258/index.htmlThird Party Advisory
https://weseek.co.jp/security/2021/09/17/vulnerability/growi-prevent-multiple-xss-addition/Vendor Advisory
https://jvn.jp/en/vu/JVNVU94889258/index.htmlThird Party Advisory
https://weseek.co.jp/security/2021/09/17/vulnerability/growi-prevent-multiple-xss-addition/Vendor Advisory

Timeline

Published: Sep 21, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-20829?

How severe is CVE-2021-20829?

CVE-2021-20829 has a CVSS score of 6.1/10 (MEDIUM severity). The EPSS model estimates a 0.73% probability of exploitation in the next 30 days.

How do I fix CVE-2021-20829?

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-2021-20829?

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

Scan your code now

Source: NVD / NIST