CVE-2023-23397 — Microsoft Outlook Elevation of Privilege Vulnerability

Executive Summary

None

Overview

9.8

CVSS CRITICAL

Critical

MS Severity

Exploited

MS Exploit Status

Exploitation Detected

MS Exploit Likelihood

Category Elevation of Privilege

Weakness CWE-20: Improper Input Validation

Released Mar 14 2023

Last Updated Mar 14 2023

Publicly Disclosed No

CISA KEV Listed (added 2023-03-14)

Known Exploits None Known

EPSS Score 0.97408 — 0.99893 percentile

NVD CVSS 9.8 CRITICAL — matches MSRC

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C

ATTACK VECTOR

Network

ATTACK COMPLEXITY

Low

PRIVILEGES REQUIRED

None

USER INTERACTION

None

SCOPE

Unchanged

CONFIDENTIALITY

High

INTEGRITY

High

AVAILABILITY

High

EXPLOIT CODE MATURITY

Functional

REMEDIATION LEVEL

Official Fix

REPORT CONFIDENCE

Confirmed

Temporal Score: 9.1

EPSS Score

0.97408

probability of exploitation in the next 30 days

0.99893 percentile - updated 2026-08-14

View on FIRST.org

Affected Products

11 affected products

Product	KB Article	Severity	Impact	Restart Required
Microsoft 365 Apps for Enterprise for 32-bit Systems	`Click to Run (Security Update)`	Critical	Elevation of Privilege	No
Microsoft 365 Apps for Enterprise for 64-bit Systems	`Click to Run (Security Update)`	Critical	Elevation of Privilege	No
Microsoft Office 2019 for 32-bit editions	`Click to Run (Security Update)`	Critical	Elevation of Privilege	No
Microsoft Office 2019 for 64-bit editions	`Click to Run (Security Update)`	Critical	Elevation of Privilege	No
Microsoft Office LTSC 2021 for 32-bit editions	`Click to Run (Security Update)`	Critical	Elevation of Privilege	No
Microsoft Office LTSC 2021 for 64-bit editions	`Click to Run (Security Update)`	Critical	Elevation of Privilege	No
Microsoft Outlook 2013 RT Service Pack 1	`5002265 (Security Update)`	Critical	Elevation of Privilege	Maybe
Microsoft Outlook 2013 Service Pack 1 (32-bit editions)	`5002265 (Security Update)`	Critical	Elevation of Privilege	Maybe
Microsoft Outlook 2013 Service Pack 1 (64-bit editions)	`5002265 (Security Update)`	Critical	Elevation of Privilege	Maybe
Microsoft Outlook 2016 (32-bit edition)	`5002254 (Security Update)`	Critical	Elevation of Privilege	Maybe
Microsoft Outlook 2016 (64-bit edition)	`5002254 (Security Update)`	Critical	Elevation of Privilege	Maybe

Patches

3 patches

Article	Type	Restart
`Click to Run`	Security Update	No
`5002265`	Security Update	Maybe
`5002254`	Security Update	Maybe

Exploits & PoC

15 public PoCs

Unverified third-party code

Public proof-of-concept repositories aggregated from PoC-in-GitHub. They are not reviewed and may be incomplete, non-functional, or malicious — inspect the code before running anything.

Repository	Stars	Published	Description
api0cradle/CVE-2023-23397-POC-Powershell	346	2023-03-16
sqrtZeroKnowledge/CVE-2023-23397_EXPLOIT_0DAY	158	2023-03-15	Exploit for the CVE-2023-23397
Trackflaw/CVE-2023-23397	132	2023-03-20	Simple PoC of the CVE-2023-23397 vulnerability with the payload sent by email.
ka7ana/CVE-2023-23397	40	2023-03-16	Simple PoC in PowerShell for CVE-2023-23397
tiepologian/CVE-2023-23397	25	2023-03-21	Proof of Concept for CVE-2023-23397 in Python
Muhammad-Ali007/OutlookNTLM_CVE-2023-23397	22	2023-07-14
BronzeBee/cve-2023-23397	14	2023-03-22	Python script for sending e-mails with CVE-2023-23397 payload using SMTP
djackreuter/CVE-2023-23397-PoC	9	2023-03-18
vlad-a-man/CVE-2023-23397	8	2023-05-07	CVE-2023-23397 PoC
BillSkiCO/CVE-2023-23397_EXPLOIT	7	2023-03-17	Generates meeting requests taking advantage of CVE-2023-23397. This requires the outlook thick client to send.
ahmedkhlief/CVE-2023-23397-POC	6	2023-03-17	Exploit POC for CVE-2023-23397
grn-bogo/CVE-2023-23397	4	2023-03-16	Python script to create a message with the vulenrability properties set
Pushkarup/CVE-2023-23397	4	2023-10-26	This script exploits CVE-2023-23397, a Zero-Day vulnerability in Microsoft Outlook, allowing the generation of malicious emails for testing and educational purposes.
alicangnll/CVE-2023-23397	3	2023-03-16	CVE-2023-23397 - Microsoft Outlook Vulnerability
P4x1s/CVE-2023-23397-POC	3	2023-03-31	CVE-2023-23397漏洞的简单PoC，有效载荷通过电子邮件发送。

Detection Rules

Detection available

Community detection & vulnerability-scanning rules aggregated from Sigma and Nuclei templates. Validate and tune to your environment before deploying.

Sigma rules 4

CVE-2023-23397 Exploitation Attempt critical Suspicious WebDav Client Execution Via Rundll32.EXE high Potential CVE-2023-23397 Exploitation Attempt - SMB medium Outlook Task/Note Reminder Received low

Acknowledgments

CERT-UA, Microsoft Incident Response, Microsoft Threat Intelligence

References

MSRC Advisory MITRE NVD