How severe is CVE-2021-28805?

CVE-2021-28805 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-28805 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (15th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-28805?

CVE-2021-28805 affects Qnap Qss. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-28805?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-28805 published?

CVE-2021-28805 was published on 2021-06-11 and last updated on 2026-06-17.

CVE-2021-28805

CVE-2021-28805 is a high-severity vulnerability in Qnap Qss with a CVSS 3.x base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-200.

Key facts

Severity: High (CVSS 3.x base score 7.8)
CVSS v2: 2.1
EPSS exploit prediction: 0% (15th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-200
Affected product: Qnap Qss
Published: 2021-06-11
Last modified: 2026-06-17

Description

Inclusion of sensitive information in the source code has been reported to affect certain QNAP switches running QSS. If exploited, this vulnerability allows attackers to read application data. This issue affects: QNAP Systems Inc. QSS versions prior to 1.0.3 build 20210505 on QSW-M2108-2C; versions prior to 1.0.3 build 20210505 on QSW-M2108-2S; versions prior to 1.0.3 build 20210505 on QSW-M2108R-2C; versions prior to 1.0.12 build 20210506 on QSW-M408.

Frequently asked questions

What is CVE-2021-28805?: Inclusion of sensitive information in the source code has been reported to affect certain QNAP switches running QSS. If exploited, this vulnerability allows attackers to read application data. This issue affects: QNAP Systems Inc. QSS versions prior to 1.0.3 build 20210505 on QSW-M2108-2C; versions prior to 1.0.3 build 20210505 on QSW-M2108-2S; versions prior to 1.0.3 build 20210505 on QSW-M2108R-2C; versions prior to 1.0.12 build 20210506 on QSW-M408.
How severe is CVE-2021-28805?: CVE-2021-28805 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-28805 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (15th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-28805?: CVE-2021-28805 affects Qnap Qss. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-28805?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-28805 published?: CVE-2021-28805 was published on 2021-06-11 and last updated on 2026-06-17.

References

https://www.qnap.com/zh-tw/security-advisory/qsa-21-24

Affected products (1)

cpe:2.3:a:qnap:qss:*:*:*:*:*:*:*:*

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