CVE-2021-42287

Exploitation

Exploited in the wild. Listed in the CISA Known Exploited Vulnerabilities catalog on 2022-04-11. Federal remediation due 2022-05-02. Known ransomware campaign use: reported by CISA.

SSVC decision

• ExploitationactiveCISA reports credible evidence of active exploitation.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

77.17% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 99.5% 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:H/PR:L/UI:N/S:U/C:H/I:H/A:H

NVD analysis status

Analyzed. NVD last modified this record on 2026-08-19.

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

2021-11-10 00:47Z4 YR AGO

Last updated

2026-08-19 16:27Z2 MO AGO

Reserved

2021-10-12

Assigning CNA

microsoft

Record state

PUBLISHED

Severity

High (CVSS 7.5)

CNA CVSS vector

CVSS:3.1/AV:N/AC:H/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

a41128b3c402f7f1c12fa63a109e9ec0a9a62bb97fa76d411156c4c48a34a41d

• msrc.microsoft.comActive Directory Domain Services Elevation of Privilege Vulnerabilityhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-42287vendor-advisorypatch
• portal.msrc.microsoft.comhttps://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-42287x_refsource_MISC
• www.cisa.govhttps://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-42287government-resource