Vulnerability in Microsoft Exchange Server 2016 Cumulative Update 23
CVE-2023-21709
Microsoft Exchange Server Elevation of Privilege Vulnerability
EPSS: 0.034 (87.6th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C.
Affected products
- Microsoft Exchange Server 2016 Cumulative Update 23 — versions 15.01.0
- Microsoft Exchange Server 2019 Cumulative Update 12 — versions 15.02.0
- Microsoft Exchange Server 2019 Cumulative Update 13 — versions 15.02.0
Weakness classification (CWE)
Public proof-of-concept exploits
References
- Microsoft Exchange Server Elevation of Privilege Vulnerability (vendor-advisory)
Frequently asked questions
- What is CVE-2023-21709?
- CVE-2023-21709 is a critical-severity vulnerability in Microsoft Exchange Server 2016 Cumulative Update 23, classified under Improper Restriction of Excessive Authentication Attempts. CVSS score: 9.8/10. Published 2023-08-08.
- How severe is CVE-2023-21709?
- Critical severity. CVSS v3 base score is 9.8 out of 10.
- Is CVE-2023-21709 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.