Microsoft Exchange Server Remote Code Execution Vulnerability

cisa required action Apply updates per vendor instructions.

1. 2022-09-28 First public exploit (Metasploit exploit/windows/http/exchange_proxynotshell_rce)
2. 2022-09-30 Added to CISA KEV
3. 2022-10-03 Published
4. 2022-10-21 CISA patch deadline
5. 2022-11-08 0-day patched (Project Zero)
6. 2025-02-04 CISA SSVC: exploitation active

Added

4 y ago (2022-09-30)

Patch by

2022-10-21 (4 y ago)

Ransomware

Known to be used in ransomware campaigns

Required action

Apply updates per vendor instructions.

Vendor, product

Microsoft, Exchange Server

CISA name

Microsoft Exchange Server Remote Code Execution Vulnerability

Detected in real attacks while still unknown to the vendor and the public, per Google Project Zero's 0day In-the-Wild tracker.

Patched

2022-11-08

Details

project zero tracker

Groups reported to have exploited it in intrusions.

• PLAY ransomware gang

reported by cisa.gov

Ransomware Vulnerability Matrix by BushidoUK (github.com/BushidoUK/Ransomware-Vulnerability-Matrix), reformatted per CVE. CC BY 4.0

How it is exploited and what it leads to, in MITRE ATT&CK terms.

• T1059.001 PowerShell exploitation
• T1078 Valid Accounts exploitation
• T1059.001 PowerShell primary impact
• T1087 Account Discovery secondary impact
• T1482 Domain Trust Discovery secondary impact
• T1505.003 Web Shell secondary impact
• T1567 Exfiltration Over Web Service secondary impact

kev release 2025-07-28, att&ck v16.1. KEV to ATT&CK mappings by the MITRE Center for Threat-Informed Defense (Mappings Explorer, Apache-2.0). © 2026 The MITRE Corporation. This work is reproduced and distributed with the permission of The MITRE Corporation. Terms of use

Exploitation

Active, exploited in the wild

Automatable

no

Technical impact

total

Assessed

21 mo ago (2025-02-04)

99.97% chance of exploitation in the next 30 days, higher than 99.9% of all scored CVEs (FIRST EPSS, 2026-11-08).

• Metasploit exploit/windows/http/exchange_proxynotshell_rce Microsoft Exchange ProxyNotShell RCE metasploit exploit, excellent rank, 2022-09-28
• packetstormsecurity.com http://packetstormsecurity.com/files/170066/Microsoft-Exchange-ProxyNotShell-Remote-Code-Execution.html referenced PoC, tagged "exploit" by a source, unverified

• Microsoft Microsoft Exchange Server 2013 Cumulative Update 23
• Microsoft Microsoft Exchange Server 2016 Cumulative Update 22
• Microsoft Microsoft Exchange Server 2019 Cumulative Update 11
• Microsoft Microsoft Exchange Server 2019 Cumulative Update 12
• Microsoft Microsoft Exchange Server 2016 Cumulative Update 23

Weakness

• CWE-502 Deserialization of Untrusted Data

Technology feeds

• Microsoft Exchange rss critical rss

• portal.msrc.microsoft.com /en-US/security-guidance/advisory/CVE-2022-41082

  patch, vendor-advisory

• packetstormsecurity.com /files/170066/Microsoft-Exchange-ProxyNotShell-Remote-Code-Execution.html

  exploit, third-party-advisory, vdb-entry

• msrc.microsoft.com /update-guide/vulnerability/CVE-2022-41082

  vendor-advisory

• vicarius.io /vsociety/posts/cve-2022-41082-microsoft-exchange-server-remote-code-execution-vulnerability-detection-script

  third-party-advisory

• vicarius.io /vsociety/posts/cve-2022-41082-microsoft-exchange-server-remote-code-execution-vulnerability-mitigation-script

  third-party-advisory

• kb.cert.org /vuls/id/915563

  third-party-advisory, us-government-resource

• secpod.com /blog/microsoft-november-2022-patch-tuesday-patches-65-vulnerabilities-including-6-zero-days/

  third-party-advisory

• cisa.gov /known-exploited-vulnerabilities-catalog?field_cve=CVE-2022-41082

  government-resource, us-government-resource

• CVE List CVE-2022-41082
• NVD CVE-2022-41082

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.