What is CVE-2022-41040?
Microsoft Exchange Server Elevation of Privilege Vulnerability
The record classifies CVE-2022-41040 under weakness class CWE-918. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs low-privilege credentials, needs no user interaction, and has high impact on confidentiality, integrity, availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 1487 days ago.
Severity and exploitation probability
- CVSS v3.1 base score
- 8.8 — HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C - EPSS (FIRST)
- 99.9% probability of exploitation in the next 30 days, higher than 99.9% of all scored CVEs
- CISA KEV
- Listed since 2022-09-30, federal remediation deadline 2022-10-21 — used in known ransomware campaigns
- Threadlinqs priority
- 10/10 — CISA lists it as used in ransomware, which Threadlinqs scores at the maximum
- Published
- 2022-10-03, last modified 2025-10-21
Is CVE-2022-41040 being exploited?
CISA added CVE-2022-41040 to the Known Exploited Vulnerabilities catalog on 2022-09-30, which means the agency holds evidence of exploitation in the wild; US federal civilian agencies had to remediate it by 2022-10-21 under BOD 22-01. CISA flags the vulnerability as one used in known ransomware campaigns. Weaponised exploit code for CVE-2022-41040 is publicly available. 10 public proof-of-concept repositories are tracked for this identifier. It currently carries a trending score of 48 in the Threadlinqs vulnerability feed.
- kljunowsky/CVE-2022-41040-POC (github)
- TaroballzChen/CVE-2022-41040-metasploit-ProxyNotShell (github)
- numanturle/CVE-2022-41040 (github)
- r3dcl1ff/CVE-2022-41040 (github)
- d3duct1v/CVE-2022-41040 (github)
- rjsudlow/proxynotshell-IOC-Checker (github)
- ITPATJIDR/CVE-2022-41040 (github)
- CentarisCyber/CVE-2022-41040_Mitigation (github)
Affected products and versions
- Microsoft: Exchange Server
How to fix CVE-2022-41040
The record marks a vendor fix as available for CVE-2022-41040. Patch reference: https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2022-41040. Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2022-41040. Because CVE-2022-41040 is KEV-listed, US federal civilian agencies were required to apply the vendor fix, or stop using the product, by 2022-10-21. Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.
Threat activity tracking CVE-2022-41040
5 tracked threats in the Threadlinqs corpus reference CVE-2022-41040, either in the campaign’s CVE list or as an indicator on the campaign record.
- FamousSparrow APT Targets Azerbaijani Oil & Gas Sector via ProxyShell/ProxyNotShell Exchange Exploitation — CRITICAL · 2026-08-23
- US Indicts Alleged Operators of Media Land Bulletproof Hosting Service Used by LockBit, BlackSuit, and Play Ransomware — HIGH · 2026-07-15
- SharkLoader Malware Campaign Uses Fake Cisco AnyConnect and Google Update Installers to Deploy Cobalt Strike — HIGH · 2026-07-03
- FamousSparrow APT Targets Azerbaijani Oil & Gas Industry via Exchange ProxyShell/ProxyNotShell (Deed RAT, Terndoor, Mofu Loader) — CRITICAL · 2026-06-10
- FamousSparrow APT Multi-Wave Intrusion at Azerbaijani Oil & Gas Company — Evolved Two-Stage DLL Sideloading Delivers Deed RAT (0xFF66ABCD) and Terndoor via Mofu Loader — CRITICAL · 2026-05-13
Sources
Enriched from CVE.org, FIRST EPSS, CISA KEV, public proof-of-concept repositories. Last verified by Threadlinqs on .