CVE-2021-34523

  1. OpenCVE
  2. Vulnerabilities (CVE)
  3. CVE-2021-34523
Microsoft Exchange Server Elevation of Privilege Vulnerability

9.0 /10

CVSS v3 : CRITICAL

V3 Legend

Vector :

Exploitability : 2.5 / Impact : 5.8

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact NONE

Scope CHANGED

7.5 /10

CVSS v2.0 : HIGH

V2 Legend

Vector : AV:N/AC:L/Au:N/C:P/I:P/A:P

Exploitability : 10.0 / Impact : 6.4

Access Vector NETWORK

Access Complexity LOW

Authentication NONE

Confidentiality Impact PARTIAL

Integrity Impact PARTIAL

Availability Impact PARTIAL

References
Link Resource
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
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
Configurations

Configuration 1 (hide)

OR cpe:2.3:a:microsoft:exchange_server:2013:cumulative_update_23:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_19:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_20:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_8:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_9:*:*:*:*:*:*
History

30 Oct 2025, 19:13

Type Values Removed Values Added
References () https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-34523 - () https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-34523 - US Government Resource

22 Oct 2025, 00:17

Type Values Removed Values Added
References
  • () https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-34523 -

21 Oct 2025, 20:18

Type Values Removed Values Added
References
  • {'url': 'https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-34523', 'source': '134c704f-9b21-4f2e-91b3-4a467353bcc0'}

21 Oct 2025, 19:19

Type Values Removed Values Added
CWE CWE-287 NVD-CWE-noinfo
References
  • () https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-34523 -

21 Nov 2024, 06:10

Type Values Removed Values Added
References () http://packetstormsecurity.com/files/163895/Microsoft-Exchange-ProxyShell-Remote-Code-Execution.html - Exploit, Third Party Advisory, VDB Entry () http://packetstormsecurity.com/files/163895/Microsoft-Exchange-ProxyShell-Remote-Code-Execution.html - Exploit, Third Party Advisory, VDB Entry
References () https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34523 - Patch, Vendor Advisory () https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34523 - Patch, Vendor Advisory
References () https://www.zerodayinitiative.com/advisories/ZDI-21-822/ - Third Party Advisory, VDB Entry () https://www.zerodayinitiative.com/advisories/ZDI-21-822/ - Third Party Advisory, VDB Entry

28 Dec 2023, 23:15

Type Values Removed Values Added
CVSS v2 : 7.5
v3 : 9.8 		v2 : 7.5
v3 : 9.0
Summary Microsoft Exchange Server Elevation of Privilege Vulnerability This CVE ID is unique from CVE-2021-33768, CVE-2021-34470. Microsoft Exchange Server Elevation of Privilege Vulnerability
Information

Published : 2021-07-14 18:15

Updated : 2025-10-30 19:13

NVD link : CVE-2021-34523

Mitre link : CVE-2021-34523

CVE.ORG link : CVE-2021-34523

JSON object : View

Products Affected

microsoft

  • exchange_server
CWE
NVD-CWE-noinfo