CVEvulnerability
CVE-2021-33766
CISA Known Exploited Vulnerability
Microsoft Exchange Server Information Disclosure — Microsoft Exchange Server
Microsoft Exchange Server contains an information disclosure vulnerability which can allow an unauthenticated attacker to steal email traffic from target.
- Added to KEV
- 2022-01-18
- Remediation due
- 2022-02-01
- Ransomware use
- Unknown
- Required action
- Apply updates per vendor instructions.
- Notes
- https://nvd.nist.gov/vuln/detail/CVE-2021-33766
- Status
- Analyzed
- Published
- 2021-07-14
- Last modified
- 2026-08-10
- Assigner
- [email protected]
- CVSS 3.1 ([email protected])
- 7.3 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
- CVSS 3.1 ([email protected])
- 7.5 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- CVSS 2.0 ([email protected])
- 5.0 MEDIUM — AV:N/AC:L/Au:N/C:P/I:N/A:N
Description
Microsoft Exchange Server Information Disclosure Vulnerability
Affected configurations
• microsoft exchange server 2013
• microsoft exchange server 2016
• microsoft exchange server 2019
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-33766 Patch, Vendor Advisory
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-33766 Patch, Vendor Advisory
- https://www.zerodayinitiative.com/advisories/ZDI-21-798/ Third Party Advisory, VDB Entry
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-33766 US Government Resource