CVE-2021-34470

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 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

4.37% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 90.9% of scored records. A rank, not a probability.

NVD base score

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

NVD CVSS vector

CVSS:3.1/AV:A/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

2021-07-14 17:54Z5 YR AGO

Last updated

2026-08-10 15:12Z2 MO AGO

Reserved

2021-06-09

Assigning CNA

microsoft

Record state

PUBLISHED

Severity

High (CVSS 8.0)

CNA CVSS vector

CVSS:3.1/AV:A/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

bb3c08e449739fc49d4e69f367733d6613c7b5117a2d9ef0cf095bb6507ec70e

• msrc.microsoft.comMicrosoft Exchange Server Elevation of Privilege Vulnerabilityhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-34470vendor-advisorypatch
• portal.msrc.microsoft.comhttps://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34470x_refsource_MISC
• packetstormsecurity.comhttp://packetstormsecurity.com/files/163706/Microsoft-Exchange-AD-Schema-Misconfiguration-Privilege-Escalation.htmlx_refsource_MISC