NVD - CVE-2021-34473 (original) (raw)
Metrics
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:
NIST: NVD
NVD assessment not yet provided.
CVSS 3.x Severity and Vector Strings:
NIST: NVD
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA: Microsoft Corporation
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CVSS 2.0 Severity and Vector Strings:
NIST: NVD
Vector: (AV:N/AC:L/Au:N/C:C/I:C/A:C)
References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| http://packetstormsecurity.com/files/163895/Microsoft-Exchange-ProxyShell-Remote-Code-Execution.html | CVE, Microsoft Corporation | Exploit Third Party Advisory VDB Entry |
| https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34473 | CVE, Microsoft Corporation | Patch Vendor Advisory |
| https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-34473 | CISA-ADP | US Government Resource |
| https://www.zerodayinitiative.com/advisories/ZDI-21-821/ | CVE, Microsoft Corporation | Third Party Advisory VDB Entry |
This CVE is in CISA's Known Exploited Vulnerabilities Catalog
Reference CISA's BOD 22-01 and Known Exploited Vulnerabilities Catalog for further guidance and requirements.
| Vulnerability Name | Date Added | Due Date | Required Action |
|---|---|---|---|
| Microsoft Exchange Server Remote Code Execution Vulnerability | 11/03/2021 | 11/17/2021 | Apply updates per vendor instructions. |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-918 | Server-Side Request Forgery (SSRF) | NIST CISA-ADP |
Known Affected Software Configurations Switch to CPE 2.2
Change History
15 change records found show changes
Modified Analysis by NIST 10/29/2025 12:46:45 PM
| Action | Type | Old Value | New Value |
|---|---|---|---|
| Added | Reference Type | CISA-ADP: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field\_cve=CVE-2021-34473 Types: US Government Resource |
CVE Modified by CISA-ADP 10/21/2025 8:17:37 PM
| Action | Type | Old Value | New Value |
|---|---|---|---|
| Added | Reference | https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field\_cve=CVE-2021-34473 |
CVE Modified by CISA-ADP 10/21/2025 4🔞37 PM
| Action | Type | Old Value | New Value |
|---|---|---|---|
| Removed | Reference | https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field\_cve=CVE-2021-34473 |
CVE Modified by CISA-ADP 10/21/2025 3:19:08 PM
| Action | Type | Old Value | New Value |
|---|---|---|---|
| Added | Reference | https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field\_cve=CVE-2021-34473 |
Modified Analysis by NIST 2/24/2025 10:47:45 AM
| Action | Type | Old Value | New Value |
|---|
CVE Modified by CISA-ADP 2/04/2025 11:15:33 AM
| Action | Type | Old Value | New Value |
|---|---|---|---|
| Added | CWE | CWE-918 |
CVE Modified by CVE 11/21/2024 1:10:29 AM
| Action | Type | Old Value | New Value |
|---|---|---|---|
| Added | Reference | http://packetstormsecurity.com/files/163895/Microsoft-Exchange-ProxyShell-Remote-Code-Execution.html | |
| Added | Reference | https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34473 | |
| Added | Reference | https://www.zerodayinitiative.com/advisories/ZDI-21-821/ |
Modified Analysis by NIST 7/26/2024 3:26:02 PM
| Action | Type | Old Value | New Value |
|---|
CVE Modified by Microsoft Corporation 5/14/2024 5:13:29 AM
| Action | Type | Old Value | New Value |
|---|
CVE Modified by Microsoft Corporation 12/28/2023 6:15:32 PM
| Action | Type | Old Value | New Value |
|---|---|---|---|
| Changed | Description | Microsoft Exchange Server Remote Code Execution Vulnerability This CVE ID is unique from CVE-2021-31196, CVE-2021-31206. | Microsoft Exchange Server Remote Code Execution Vulnerability |
| Added | CVSS V3.1 | Microsoft Corporation AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N |
CWE Remap by NIST 7/12/2022 1:42:04 PM
| Action | Type | Old Value | New Value |
|---|---|---|---|
| Changed | CWE | NVD-CWE-noinfo | CWE-918 |
Modified Analysis by NIST 9/21/2021 1:38:08 PM
| Action | Type | Old Value | New Value |
|---|---|---|---|
| Changed | Reference Type | http://packetstormsecurity.com/files/163895/Microsoft-Exchange-ProxyShell-Remote-Code-Execution.html No Types Assigned | http://packetstormsecurity.com/files/163895/Microsoft-Exchange-ProxyShell-Remote-Code-Execution.html Exploit, Third Party Advisory, VDB Entry |
| Changed | Reference Type | https://www.zerodayinitiative.com/advisories/ZDI-21-821/ Third Party Advisory | https://www.zerodayinitiative.com/advisories/ZDI-21-821/ Third Party Advisory, VDB Entry |
CVE Modified by Microsoft Corporation 8/20/2021 2:15:07 PM
| Action | Type | Old Value | New Value |
|---|---|---|---|
| Added | Reference | http://packetstormsecurity.com/files/163895/Microsoft-Exchange-ProxyShell-Remote-Code-Execution.html [No Types Assigned] |
Initial Analysis by NIST 7/19/2021 11:35:37 AM
| Action | Type | Old Value | New Value |
|---|---|---|---|
| Added | CVSS V3.1 | NIST AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H | |
| Added | CVSS V2 | NIST (AV:N/AC:L/Au:N/C:C/I:C/A:C) | |
| Added | CWE | NIST NVD-CWE-noinfo | |
| Added | CPE Configuration | 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:*:*:*:*:*:* | |
| Changed | Reference Type | https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34473 No Types Assigned | https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34473 Patch, Vendor Advisory |
| Changed | Reference Type | https://www.zerodayinitiative.com/advisories/ZDI-21-821/ No Types Assigned | https://www.zerodayinitiative.com/advisories/ZDI-21-821/ Third Party Advisory |
CVE Modified by Microsoft Corporation 7/19/2021 6:15:08 AM
| Action | Type | Old Value | New Value |
|---|---|---|---|
| Added | Reference | https://www.zerodayinitiative.com/advisories/ZDI-21-821/ [No Types Assigned] |