CVEvulnerability
CVE-2021-34523
CISA Known Exploited Vulnerability
Microsoft Exchange Server Privilege Escalation Vulnerability — Microsoft Exchange Server
Microsoft Exchange Server contains an unspecified vulnerability that allows for privilege escalation.
- Added to KEV
- 2021-11-03
- Remediation due
- 2021-11-17
- Ransomware use
- Known
- Required action
- Apply updates per vendor instructions.
- Notes
- https://nvd.nist.gov/vuln/detail/CVE-2021-34523
- Status
- Analyzed
- Published
- 2021-07-14
- Last modified
- 2026-08-10
- Assigner
- [email protected]
- CVSS 3.1 ([email protected])
- 9.0 CRITICAL — CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N
- CVSS 3.1 ([email protected])
- 9.8 CRITICAL — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CVSS 2.0 ([email protected])
- 7.5 HIGH — AV:N/AC:L/Au:N/C:P/I:P/A:P
Description
Microsoft Exchange Server Elevation of Privilege Vulnerability
Affected configurations
• microsoft exchange server 2013
• microsoft exchange server 2016
• microsoft exchange server 2019
Related
Referenced by CWE · observed example (1)
- CWE-287 Improper Authentication weakness
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-34523 Patch, Vendor Advisory
- http://packetstormsecurity.com/files/163895/Microsoft-Exchange-ProxyShell-Remote-Code-Execution.html Exploit, Third Party Advisory, VDB Entry
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34523 Patch, Vendor Advisory
- https://www.zerodayinitiative.com/advisories/ZDI-21-822/ Third Party Advisory, VDB Entry
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-34523 US Government Resource