Auth bypass in Microsoft Exchange Server 2016 Cumulative Update 23
CVE-2024-21410
Microsoft Exchange Server Elevation of Privilege Vulnerability
Vulnerability class: Broken Authentication
EPSS: 0.061 (91.0th 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:F/RL:O/RC:C.
Affected products
- Microsoft Exchange Server 2016 Cumulative Update 23 — versions 15.01.0
- Microsoft Exchange Server 2019 Cumulative Update 13 — versions 15.02.0
- Microsoft Exchange Server 2019 Cumulative Update 14 — versions 15.02.0
Weakness classification (CWE)
CISA KEV (Known Exploited Vulnerabilities)
This CVE is on the CISA KEV catalog, added on . CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.
BOD 22-01 due date: .
Required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Public proof-of-concept exploits
References
- Microsoft Exchange Server Elevation of Privilege Vulnerability (vendor-advisory)
Frequently asked questions
- What is CVE-2024-21410?
- CVE-2024-21410 is a critical-severity vulnerability in Microsoft Exchange Server 2016 Cumulative Update 23, classified under Improper Authentication. CVSS score: 9.8/10. Published 2024-02-13.
- How severe is CVE-2024-21410?
- Critical severity. CVSS v3 base score is 9.8 out of 10.
- Is CVE-2024-21410 known to be exploited?
- Yes. CVE-2024-21410 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2024-02-15), indicating it is being actively exploited. 9 public proof-of-concept repositories are indexed.