Vulnerability in Microsoft Exchange Server 2013 Cumulative Update 23

CVE-2021-34470

Microsoft Exchange Server Elevation of Privilege Vulnerability

EPSS: 0.037 (88.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.0 (High). 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.

Affected products

Microsoft Exchange Server 2013 Cumulative Update 23 — versions 15.00.0
Microsoft Exchange Server 2016 Cumulative Update 21 — versions 15.01.0
Microsoft Exchange Server 2019 Cumulative Update 10 — versions 15.02.0

Public proof-of-concept exploits

References

portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34470 (x_refsource_MISC)
packetstormsecurity.com/files/163706/Microsoft-Exchange-AD-Schema-Misconfigurat… (x_refsource_MISC)

Frequently asked questions

What is CVE-2021-34470?: CVE-2021-34470 is a high-severity vulnerability in Microsoft Exchange Server 2013 Cumulative Update 23. CVSS score: 8.0/10. Published 2021-07-14.
How severe is CVE-2021-34470?: High severity. CVSS v3 base score is 8.0 out of 10.
Is CVE-2021-34470 known to be exploited?: 5 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.