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

Published Mar 14, 2023
·
Updated

Microsoft Office Outlook contains a privilege escalation vulnerability that allows for a NTLM Relay attack against another service to authenticate as the user.

Other sources

Microsoft Outlook Elevation of Privilege Vulnerability

Affected Software

20 affected componentsFixes available
Microsoft Office
Microsoft 365 Apps
Microsoft Office=2019
Microsoft Office=2021
Microsoft Outlook=2013-sp1
Microsoft Outlook=2013-sp1
Microsoft Outlook=2016
Microsoft Office Long Term Servicing Channel=2021
Microsoft Outlook=2013-sp1
Microsoft Outlook 2016<16.0.5387.1000
16.0.5387.1000
Microsoft Office 2019 for 32-bit editions<https://aka.ms/OfficeSecurityReleases
https://aka.ms/OfficeSecurityReleases
Microsoft Outlook 2013 RT<15.0.5537.1000
15.0.5537.1000
Microsoft Office 2019 for 64-bit editions<https://aka.ms/OfficeSecurityReleases
https://aka.ms/OfficeSecurityReleases
Microsoft 365 Apps for Enterprise<https://aka.ms/OfficeSecurityReleases
https://aka.ms/OfficeSecurityReleases
Microsoft Office LTSC 2021 for 64-bit editions<https://aka.ms/OfficeSecurityReleases
https://aka.ms/OfficeSecurityReleases
Microsoft 365 Apps for Enterprise<https://aka.ms/OfficeSecurityReleases
https://aka.ms/OfficeSecurityReleases
Microsoft Outlook 2016<16.0.5387.1000
16.0.5387.1000
Microsoft Outlook 2013<15.0.5537.1000
15.0.5537.1000
Microsoft Outlook 2013<15.0.5537.1000
15.0.5537.1000
Microsoft Office LTSC 2021 for 32-bit editions<https://aka.ms/OfficeSecurityReleases
https://aka.ms/OfficeSecurityReleases

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in https://aka.ms/OfficeSecurityReleases
  2. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 16.0.5387.1000Patch KB5002254
  3. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 15.0.5537.1000Patch KB5002265

Event History

Mar 14, 2023
CVE Published
via CISA·12:00 AM
Known Exploited
via CISA·12:00 AM
Data Sourced
07:00 AM
DescriptionSeverityWeakness
Data Sourced
via Microsoft·07:00 AM
DescriptionSeverityWeaknessAffected Software
Updated
via Microsoft·07:00 AM
Affected Software
Updated
via Microsoft·07:00 AM
Description
CVE Published
via MITRE·04:55 PM
Data Sourced
via MITRE·04:55 PM
DescriptionSeverity
Data Sourced
via NVD·05:15 PM
RemedyDescriptionSeverityWeaknessAffected Software
Dec 6, 2023
News Published
12:15 AM
Dec 7, 2023
News Published
10:20 PM
May 3, 2024
News Published
via BleepingComputer·03:47 PM
May 7, 2024
News Published
via BleepingComputer·03:50 PM
May 9, 2024
News Published
via BleepingComputer·11:14 PM
Feb 12, 2025
News Published
via Dark Reading·05:00 PM
News Published
via Dark Reading·05:00 PM
Feb 25, 2025
News Published
via The Register·11:00 AM
News Published
via The Register·11:03 AM
May 21, 2025
News Published
via BleepingComputer·02:02 PM
News Published
via The Register·07:16 PM
Sep 8, 2025
News Published
via The Register·11:46 AM

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Frequently Asked Questions

1

What is CVE-2023-23397?

CVE-2023-23397 is a privilege escalation vulnerability in Microsoft Office Outlook.

2

What is the severity of CVE-2023-23397?

CVE-2023-23397 has a severity level of critical.

3

How does CVE-2023-23397 affect Microsoft Office Outlook?

CVE-2023-23397 allows for an NTLM Relay attack against another service to authenticate as the user.

4

Which versions of Microsoft Office are affected by CVE-2023-23397?

Microsoft Office versions including Office 2019, Office 365 Apps for Enterprise, and Office LTSC 2021 are affected by CVE-2023-23397.

5

How can I mitigate CVE-2023-23397 in Microsoft Office Outlook?

To mitigate CVE-2023-23397, apply the security updates provided by Microsoft for the affected versions of Microsoft Office Outlook.

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