CVE-2023-23397 is a critical elevation of privilege vulnerability affecting Microsoft Outlook. This has a severity score of 9.8. Users should be aware of this vulnerability and take necessary precautions to protect their systems.

How do I know if I'm affected?

If you're using Microsoft Outlook, you might be affected by the vulnerability. This vulnerability impacts various software configurations, including Microsoft 365 Apps, Microsoft Office 2019, Microsoft Office 2021, Microsoft Outlook 2013 SP1, Microsoft Outlook 2016, and others. To know if you're affected, check the version of your Microsoft Outlook or Office software and compare it to the list of affected versions mentioned above.

What should I do if I'm affected

If you're affected by the CVE-2023-23397 vulnerability, follow these steps: 1) Update your Microsoft Outlook or Office software to the latest version, which includes security patches. 2) Add users to the Protected Users Security Group. 3) Block TCP 445/SMB outbound from your network. These measures help prevent unauthorized access and protect your system.

Is this in CISA’s Known Exploited Vulnerabilities Catalog?

Yes, it is in CISA's Known Exploited Vulnerabilities Catalog. The vulnerability, named Microsoft Office Outlook Privilege Escalation Vulnerability, was added on March 14, 2023, with a due date of April 4, 2023. The required action is to apply updates according to vendor instructions to protect your system from this elevation of privilege issue.

Weakness enumeration

The weakness enumeration for this vulnerability is CWE-294, which is an "Authentication Bypass by Capture-replay" weakness, which can lead to unauthorized access and privilege escalation in Microsoft Outlook.

For more details

The CVE-2023-23397 vulnerability is a critical elevation of privilege issue affecting Microsoft Outlook. Users should take necessary precautions and update their software to protect their systems. For a comprehensive understanding of this vulnerability, refer to the NVD page or the links below.

• NVD - CVE-2023-23397

• Microsoft Security Update Guide

• CISA's Binding Operational Directive 22-01

• CISA's Known Exploited Vulnerabilities Catalog