CVE-2021-28798

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

0.93% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 60.5% of scored records. A rank, not a probability.

NVD base score

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

NVD CVSS vector

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

2021-05-21 03:00Z5 YR AGO

Last updated

2024-09-16 18:49Z2 YR AGO

Reserved

2021-03-18

Assigning CNA

qnap

Record state

PUBLISHED

Severity

High (CVSS 8.8)

CNA CVSS vector

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

Weaknesses

• CWE-23Relative Path TraversalBase
• CWE-284Improper Access ControlPillar
• CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')Base

Data version

5.1

Document digest

4b1c63b4af129d3d1f6056dbdd6194035a0c1282d832eb57779457491c9e7ace

• www.qnap.comhttps://www.qnap.com/zh-tw/security-advisory/qsa-21-14x_refsource_MISC