CVE-2021-27648

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

2.84% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 86.4% of scored records. A rank, not a probability.

NVD base score

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

NVD CVSS vector

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

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

2021-04-28 07:25Z5 YR AGO

Last updated

2024-09-16 16:58Z2 YR AGO

Reserved

2021-02-24

Assigning CNA

synology

Record state

PUBLISHED

Severity

Critical (CVSS 9.0)

CNA CVSS vector

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

Weaknesses

• CWE-610Externally Controlled Reference to a Resource in Another SphereClass

Data version

5.1

Document digest

377fc0bb54a91b5e34ccf13c5d56f4dde083bfc43b3312815f8e105652fc27b6

• www.synology.comhttps://www.synology.com/security/advisory/Synology_SA_21_15x_refsource_CONFIRM