What is CVE-2021-38680?

CVE-2021-38680 is a medium-severity vulnerability in Linn Products Limited Kazoo Server, classified under Cross-site Scripting. CVSS score: 5.3/10. Published 2021-12-29.

How severe is CVE-2021-38680?

Medium severity. CVSS v3 base score is 5.3 out of 10.

XSS in Linn Products Limited Kazoo Server

CVE-2021-38680

A cross-site scripting (XSS) vulnerability has been reported to affect QNAP device running Kazoo Server. If exploited, this vulnerability allows remote attackers to inject malicious code. We have already fixed this vulnerability in the following versions of Kazoo Server: Kazoo Server 4.11.20 and later

Vulnerability class: XSS (Cross-Site Scripting)

Published 2021-12-29 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.007 (51.0th percentile), scored 2026-10-03.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 51st percentile — 51.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: 0.000

Affected products

Linn Products Limited Kazoo Server — versions unspecified
QNAP Kazoo Server

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

www.qnap.com/en/security-advisory/qsa-21-54 (Vendor Advisory)

Frequently asked questions

What is CVE-2021-38680?: CVE-2021-38680 is a medium-severity vulnerability in Linn Products Limited Kazoo Server, classified under Cross-site Scripting. CVSS score: 5.3/10. Published 2021-12-29.
How severe is CVE-2021-38680?: Medium severity. CVSS v3 base score is 5.3 out of 10.