CVE-2021-28447

Exploitation

Public exploit code exists. CISA's assessment records a public proof of concept. That is not a report of exploitation in the wild.

SSVC decision

• ExploitationpocPublic proof-of-concept exploit code exists. Not a report of exploitation in the wild.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpactpartialSuccessful exploitation gives limited 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

2.04% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 81.0% of scored records. A rank, not a probability.

NVD base score

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

NVD CVSS vector

CVSS:3.1/AV:L/AC:L/PR:H/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

2021-04-13 19:33Z5 YR AGO

Last updated

2024-11-19 16:32Z1 YR AGO

Reserved

2021-03-15

Assigning CNA

microsoft

Record state

PUBLISHED

Severity

Medium (CVSS 4.4)

CNA CVSS vector

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

Weaknesses

No CWE assigned

Data version

5.1

Document digest

3610fcc6aac44492663281ee42c7b536df4b869efa3ec1796075356d4114fbf1

• portal.msrc.microsoft.comhttps://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-28447x_refsource_MISC
• bi-zone.medium.comhttps://bi-zone.medium.com/measured-boot-and-malware-signatures-exploring-two-vulnerabilities-found-in-the-windows-loader-5a4fcc3c4b66x_refsource_MISC