CVE-2021-28807

Exploitation

Not assessed. CISA has not published an exploitation assessment for this record, and it is not in the KEV catalog. That is an absence of assessment, not a finding of no risk.

SSVC decision

Not assessed by CISA

EPSS probability

1.38% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 70.2% of scored records. A rank, not a probability.

NVD base score

5.4 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

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

NVD analysis status

Modified. NVD last modified this record on 2026-06-17.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2021-06-03 02:45Z5 YR AGO

Last updated

2024-09-16 17:17Z1 YR AGO

Reserved

2021-03-18

Assigning CNA

qnap

Record state

PUBLISHED

Severity

High (CVSS 7.7)

CNA CVSS vector

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

Weaknesses

• CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')Base

Data version

5.1

Document digest

4f2e2821b227a6f18c5f6def6e0242b2e6b60d6b7bb3ef81ebd84b2ed54a030a

• www.qnap.comhttps://www.qnap.com/zh-tw/security-advisory/qsa-21-20x_refsource_MISC
• www.shielder.ithttps://www.shielder.it/advisories/qnap-qcenter-virtual-stored-xss/x_refsource_MISC
• www.shielder.ithttps://www.shielder.it/advisories/qnap-qcenter-post-auth-remote-code-execution-via-qpkg/x_refsource_MISC