Overview
Microsoft Office Outlook contains a privilege escalation vulnerability that allows for a NTLM Relay attack against another service to authenticate as the user.
https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2023-23397, https://msrc.microsoft.com/blog/2023/03/microsoft-mitigates-outlook-elevation-of-privilege-vulnerability/, ; https://nvd.nist.gov/vuln/detail/CVE-2023-23397
Key Details
| Property | Value |
|---|---|
| CVE ID | CVE-2023-23397 |
| Vendor / Product | Microsoft — Office |
| NVD Published | 2023-03-14 |
| NVD Last Modified | 2025-10-27 |
| CVSS 3.1 Score | 9.8 |
| CVSS 3.1 Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| Severity | CRITICAL |
| CWE | CWE-20 |
| CISA KEV Added | 2023-03-14 |
| CISA KEV Deadline | 2023-04-04 |
| Known Ransomware Use | No |
CVSS 3.1 Breakdown
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Required Action
CISA BOD 22-01 Deadline: 2023-04-04.
Apply updates per vendor instructions.
Timeline
| Date | Event |
|---|---|
| 2023-03-14 | Added to CISA Known Exploited Vulnerabilities catalog |
| 2023-04-04 | CISA BOD 22-01 remediation deadline |
References
| Resource | Type |
|---|---|
| NVD — CVE-2023-23397 | Vulnerability Database |
| CISA KEV Catalog Entry | US Government |