CVEs / CVE-2023-23397
CVE-2023-23397: Microsoft Office Outlook Privilege Escalation Vulnerability
- Known exploited in the CISA KEV catalog since 14 Mar 2023
- critical 9.8 CVSS 3.1 (NVD)
- EPSS 97.1% chance of exploitation in the next 30 days, higher than 99% of CVEs (30 Oct 2026)
- Last changed at its sources
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Summary
Microsoft Office Outlook contains a privilege escalation vulnerability that allows for a NTLM Relay attack against another service to authenticate as the user.
Description
Microsoft Outlook Elevation of Privilege Vulnerability
Affected and fixed versions
| Product | Affected | Fixed in |
|---|---|---|
| Microsoft Microsoft Office LTSC 2021 | from 16.0.1, before https://aka.ms/OfficeSecurityReleases | https://aka.ms/OfficeSecurityReleases |
| Microsoft Microsoft Outlook 2016 | from 16.0.0.0, before 16.0.5387.1000 | 16.0.5387.1000 |
| Microsoft Microsoft 365 Apps for Enterprise | from 16.0.1, before https://aka.ms/OfficeSecurityReleases | https://aka.ms/OfficeSecurityReleases |
| Microsoft Microsoft Office 2019 | from 19.0.0, before https://aka.ms/OfficeSecurityReleases | https://aka.ms/OfficeSecurityReleases |
| Microsoft Microsoft Outlook 2013 Service Pack 1 | from 15.0.0.0, before 15.0.5537.1000 | 15.0.5537.1000 |
Exploitation
| In CISA KEV since | 14 Mar 2023 |
|---|---|
| Due date for US federal agencies | 4 Apr 2023 |
| Used in ransomware campaigns | Unknown |
| Required action | Apply updates per vendor instructions. |
Severity
| CVSS 3.1 | 9.8 criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HScored by NVD |
|---|---|
| Weakness | CWE-20, CWE-294 |
References
- CVE-2023-23397 on NVD
- CVE-2023-23397 in the CISA KEV catalog
- https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2023-23397 (cited by CISA)
- https://msrc.microsoft.com/blog/2023/03/microsoft-mitigates-outlook-elevation-of-privilege-vulnerability/ (cited by CISA)
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-23397 Patch, Vendor Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-23397 US Government Resource
Sources
Exploitation status from the CISA Known Exploited Vulnerabilities catalog. EPSS scores from FIRST. Descriptions, severity and references from the National Vulnerability Database. Open-source package versions from OSV (CC-BY 4.0). Text is shown as each source states it; Stackurity does not edit it. Check the vendor's advisory before acting.
This product uses data from the NVD API but is not endorsed or certified by the NVD.