CVE-2023-21709
Published: 08 August 2023
Summary
CVE-2023-21709 is a critical-severity Improper Restriction of Excessive Authentication Attempts (CWE-307) vulnerability in Microsoft Exchange Server. Its CVSS base score is 9.8 (Critical).
Operationally, ranked in the top 12.3% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2023-25876
Vulnerability details
Microsoft Exchange Server Elevation of Privilege Vulnerability
- CWE(s)
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
This control directly enforces limits on consecutive invalid logon attempts and automatic response (e.g., lockout) to prevent brute-force exploitation of authentication mechanisms.
Specific conditions can include excessive failed attempts, triggering stronger authentication that restricts brute-force exploitation.