CVE-2021-34442

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

3.17% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 87.5% 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 2026-08-10.

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

2021-07-16 20:19Z5 YR AGO

Last updated

2026-08-10 15:11Z2 MO AGO

Reserved

2021-06-09

Assigning CNA

microsoft

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/E:U/RL:O/RC:C

Weaknesses

No CWE assigned

Data version

5.2

Document digest

fb93bcf67e718a15afa42fa4d77e322d0db13da7e360c36ae40efc8d24923da2

• msrc.microsoft.comWindows DNS Server Remote Code Execution Vulnerabilityhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-34442vendor-advisorypatch
• portal.msrc.microsoft.comhttps://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34442x_refsource_MISC