What is CVE-2021-28815?

CVE-2021-28815 is a medium-severity vulnerability in QNAP Myqnapcloud Link, classified under CWE-922. CVSS score: 6.0/10. Published 2021-06-16.

How severe is CVE-2021-28815?

Medium severity. CVSS v3 base score is 6.0 out of 10.

Vulnerability in QNAP Myqnapcloud Link

CVE-2021-28815

Insecure storage of sensitive information has been reported to affect QNAP NAS running myQNAPcloud Link. If exploited, this vulnerability allows remote attackers to read sensitive information by accessing the unrestricted storage mechanism. This issue affects: QNAP Systems Inc. myQNAPcloud Link versions prior to 2.2.21 on QTS 4.5.3; versions prior to 2.2.21 on QuTS hero h4.5.2; versions prior to 2.2.21 on QuTScloud c4.5.4.

Published 2021-06-16 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.0 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.017 (76.6th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 77th percentile — 76.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.017 · newest: 0.017 · change: +0.000

Affected products

QNAP Myqnapcloud Link
QNAP Qts — versions 4.5.3
QNAP Qutscloud — versions c4.5.4
QNAP Quts Hero — versions h4.5.2
QNAP Systems Inc. Myqnapcloud Link — versions unspecified

Weakness classification (CWE)

CWE-922

References

www.qnap.com/zh-tw/security-advisory/qsa-21-26 (Vendor Advisory)

Frequently asked questions

What is CVE-2021-28815?: CVE-2021-28815 is a medium-severity vulnerability in QNAP Myqnapcloud Link, classified under CWE-922. CVSS score: 6.0/10. Published 2021-06-16.
How severe is CVE-2021-28815?: Medium severity. CVSS v3 base score is 6.0 out of 10.