CVE-2022-41040
ProxyNotShell
Microsoft Exchange Server Elevation of Privilege Vulnerability
- CVSS
- 8.8Highscored by the publisher (CNA)
- Exploited in the wild
- Yes, in CISA KEV since 30 Sept 2022CISA deadline for US federal agencies: 21 Oct 2022known use in ransomware campaignspublic exploit code
- EPSS
- > 99.9%chance of exploitation in the next 30 daystop 0.1% of scored CVEsFIRST score of 11 Nov 2026
- Fix
- Patch availablesee the advisories in the references
- Published
- 3 Oct 2022analysed here 12 Nov 2026
Do first. Apply updates per vendor instructions. (CISA's required action for this KEV entry)
Summary
Triage
The summary, impact and action text on this page are written by our AI analysis pipeline, or taken from the NVD description when a CVE was imported from NVD. They are not the vendor's wording: check them against the sources. A longer AI executive summary and technical analysis are generated for signed-in accounts on the Max plan.
Affected products
| Product | Affected versions | Vendor says fixed in |
|---|---|---|
| Microsoft Microsoft Exchange Server 2013 Cumulative Update 23 | >= 15.00.0 and < 15.00.1497.044Vendor says fixed in: not stated | |
| Microsoft Microsoft Exchange Server 2016 Cumulative Update 22 | >= 15.0.0 and < 15.01.2375.037Vendor says fixed in: not stated | |
| Microsoft Microsoft Exchange Server 2016 Cumulative Update 23 | >= 15.01.0 and < 15.01.2507.016Vendor says fixed in: not stated | |
| Microsoft Microsoft Exchange Server 2019 Cumulative Update 11 | >= 15.02.0 and < 15.02.0986.036Vendor says fixed in: not stated | |
| Microsoft Microsoft Exchange Server 2019 Cumulative Update 12 | >= 15.02.0 and < 15.02.1118.020Vendor says fixed in: not stated |
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.
Products named in our analysis
- microsoft:exchange_server
Fix and mitigation
WAF and other mitigations
Can a WAF block it? Partly. SSRF makes the server call a URL the attacker picks. A WAF can block well-known targets such as cloud metadata addresses, but not every internal host.
Also consider: egress filter · IMDSv2
Based on the weakness type only; no CVE-specific evidence yet. We check Cloudflare, AWS, Google Cloud Armor and Azure; for Akamai, Imperva, Fastly, F5, ask your vendor.
Remediation steps (AI-written)
Step-by-step remediation is generated for accounts on the Max plan, for CVEs that match a technology in their stack. Add this technology to your stack to see the fix checklist.
Exploitation evidence
- CISA KEV catalog
- Listed since 30 Sept 2022. Known use in ransomware campaigns.
- CISA due date
- 21 Oct 2022, the remediation deadline for US federal agencies
- CISA required action
- Apply updates per vendor instructions.
- Public exploit code
- Yes: 1 Metasploit module · 9 GitHub proofs of concept
- CISA SSVC
- exploitation active, automatable no, technical impact totalAssessed by CISA 23 Feb 2024 (SSVC 2.0.3). Exploitation is none, poc (public proof of concept) or active.
Metasploit
- exploit/windows/http/exchange_proxynotshell_rceexploit, rank excellent
GitHub proofs of concept
- kljunowsky/CVE-2022-41040-POC90 stars
- TaroballzChen/CVE-2022-41040-metasploit-ProxyNotShell35 stars
- numanturle/CVE-2022-4104019 stars
- r3dcl1ff/CVE-2022-410405 stars
and 5 more repositories
Listed so you can judge urgency, not as a recommendation to run anything. GitHub “proofs of concept” are unvetted: some are fake or carry malware. Exploit-DB marks the entries its staff verified.
Timeline
- 30 Sept 2022Added to CISA KEV (exploited in the wild)
- 2 Oct 2022First public exploit or proof of concept2 days later
- 3 Oct 2022Published1 day later
- 21 Oct 2022CISA remediation due date (US federal agencies)18 days later
- 23 Feb 2024CISA SSVC assessment: exploitation active491 days (about 1 year) later
- 21 Oct 2025CVE record last updated606 days (about 2 years) later
- 12 Nov 2026Analysed by vulneraibility.com387 days (about 1 year) later
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
| Metric | Value | What it means |
|---|---|---|
| Attack vector | NetworkReachable over the internet or any routable network. | Reachable over the internet or any routable network. |
| Attack complexity | LowRepeatable attack, no special conditions. | Repeatable attack, no special conditions. |
| Privileges required | LowThe attacker needs basic user privileges. | The attacker needs basic user privileges. |
| User interaction | NoneNo victim action needed. | No victim action needed. |
| Scope | UnchangedImpact stays within the vulnerable component. | Impact stays within the vulnerable component. |
| Confidentiality | HighTotal data disclosure possible. | Total data disclosure possible. |
| Integrity | HighComplete modification possible. | Complete modification possible. |
| Availability | HighFull outage possible. | Full outage possible. |
Common questions
Is CVE-2022-41040 being exploited?
Yes. CVE-2022-41040 appears in CISA's Known Exploited Vulnerabilities catalog, which means exploitation in the wild has been confirmed and reported. Treat it as active rather than theoretical, and patch it ahead of higher-scoring vulnerabilities that carry no exploitation evidence.
How severe is CVE-2022-41040?
CVE-2022-41040 is rated High with a CVSS score of 8.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2022-41040?
Yes. A fix has been recorded for CVE-2022-41040. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2022-41040 affect?
CVE-2022-41040 affects microsoft:exchange_server. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
References
6 references in the CVE record, grouped by the tags the record gives them.
Advisories (2)
- msrc.microsoft.com /update-guide/vulnerability/CVE-2022-41040
- kb.cert.org /vuls/id/915563
Other links (4)
- portal.msrc.microsoft.com /en-US/security-guidance/advisory/CVE-2022-41040
- packetstormsecurity.com /files/170066/Microsoft-Exchange-ProxyNotShell-Remote-Code-Execution.html
- secpod.com /blog/microsoft-november-2022-patch-tuesday-patches-65-vulnerabilities-including
- cisa.gov /known-exploited-vulnerabilities-catalog?field_cve=CVE-2022-41040
Where the data on this page comes from
- CVE List (CVE.org): description, affected versions, references; CVE Terms of Use
- NVD: CVSS and CPE data
- CISA KEV catalog: exploitation, date added, due date
- CISA Vulnrichment (ADP): SSVC decision points
- FIRST EPSS: exploit probability and percentile
- Metasploit Framework: exploit and scanner modules
- PoC-in-GitHub: GitHub repositories that claim a proof of concept
Summary, impact and triage tags: written by our AI analysis pipeline from the sources above. Check them against the sources.
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