Security News > 2023 > March > Microsoft shares tips on detecting Outlook zero-day exploitation
Microsoft today published a detailed guide aiming to help customers discover signs of compromise via exploitation of a recently patched Outlook zero-day vulnerability.
Microsoft also shared guidance on how to block future attacks targeting this vulnerability, urging organizations to install the recently released Outlook security update.
"To address this vulnerability, you must install the Outlook security update, regardless of where your mail is hosted or your organization's support for NTLM authentication," the Microsoft Incident Response team said.
"While leveraging NTLMv2 hashes to gain unauthorized access to resources is not a new technique, the exploitation of CVE-2023-23397 is novel and stealthy," the Microsoft Incident Response team added.
Microsoft fixes Outlook zero-day used by Russian hackers since April 2022.
Outlook for Mac now free, Microsoft 365 subscription not needed.
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Related Vulnerability
| DATE | CVE | VULNERABILITY TITLE | RISK |
|---|---|---|---|
| 2023-03-14 | CVE-2023-23397 | Authentication Bypass by Capture-replay vulnerability in Microsoft 365 Apps, Office and Outlook Microsoft Outlook Elevation of Privilege Vulnerability | 9.8 |