CVE-2021-33766
HIGH severity · CVSS 7.3 · actively exploited (CISA KEV)
7.3CVSS HIGH ● exploited
🔴 Actively exploited in the wild (CISA Known Exploited Vulnerabilities).
Added to KEV 2022-01-18. US federal agencies must patch by 2022-02-01.
Summary
Microsoft Exchange Server Information Disclosure Vulnerability
Impact & exploitability
Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionNone
Confidentiality impactLow
Integrity impactLow
Availability impactLow
Exploit probability (EPSS)94%
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
Affected products we track (1)
Recommendation
This vulnerability is being actively exploited in the wild — patch affected products urgently. Open any affected product above for its exact safe version.
Official patch: https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-33766 ↗
Additional information
- NVD record
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-33766Patch
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-33766Patch
- https://www.zerodayinitiative.com/advisories/ZDI-21-798/Advisory
- https://www.zerodayinitiative.com/advisories/ZDI-21-798/Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-33766