What is CVE-2021-34360?

CVE-2021-34360 is a medium-severity vulnerability in QNAP Nas Proxy Server, classified under Cross-Site Request Forgery (CSRF). CVSS score: 5.3/10. Published 2022-05-26.

How severe is CVE-2021-34360?

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

CSRF in QNAP Nas Proxy Server

CVE-2021-34360

A cross-site request forgery (CSRF) vulnerability has been reported to affect QNAP device running Proxy Server. If exploited, this vulnerability allows remote attackers to inject malicious code. We have already fixed this vulnerability in the following versions of Proxy Server: QTS 4.5.x: Proxy Server 1.4.2 ( 2021/12/30 ) and later QuTS hero h5.0.0: Proxy Server 1.4.3 ( 2022/01/18 ) and later QuTScloud c4.5.6: Proxy Server 1.4.2 ( 2021/12/30 ) and later

Vulnerability class: CSRF (Cross-Site Request Forgery)

Published 2022-05-26 · 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: 0.005 (38.3th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 38th percentile — 38.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: +0.000

Affected products

QNAP Nas Proxy Server
QNAP Qts
QNAP Qutscloud — versions c4.5.6
QNAP Quts Hero — versions h5.0.0
QNAP Systems Inc. Proxy Server — versions unspecified

Weakness classification (CWE)

CWE-352 — Cross-Site Request Forgery (CSRF)

References

www.qnap.com/en/security-advisory/qsa-22-18 (Vendor Advisory)

Frequently asked questions

What is CVE-2021-34360?: CVE-2021-34360 is a medium-severity vulnerability in QNAP Nas Proxy Server, classified under Cross-Site Request Forgery (CSRF). CVSS score: 5.3/10. Published 2022-05-26.
How severe is CVE-2021-34360?: Medium severity. CVSS v3 base score is 5.3 out of 10.