#VU73511 Information disclosure in Microsoft Outlook and Microsoft Office - CVE-2023-23397
Published: March 14, 2023 / Updated: November 22, 2024
Vulnerability identifier: #VU73511
Vulnerability risk: Critical
CVSSv4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:A/U:Red
CVE-ID: CVE-2023-23397
CWE-ID: CWE-200
Exploitation vector: Remote access
Exploit availability:
The vulnerability is being exploited in the wild
Vulnerable software:
Microsoft Outlook
Microsoft Office
Microsoft Outlook
Microsoft Office
Software vendor:
Microsoft
Microsoft
Description
The vulnerability allows a remote attacker to compromise the affected system.
The vulnerability exists due to the application leaks the Net-NTLMv2 hash. A remote attacker can send a specially crafted email to the victim and obtain the Net-NTLMv2 hash of the Windows account. The victim does not need to open the email, as the vulnerability is triggered automatically when it is retrieved and processed by the email server, e.g. before the email is viewed in the preview pane.
The obtained NTLMv2 hash can be used in the NTLM Relay attack against another service to authenticate as the user.
Note, the vulnerability is being actively exploited in the wild.
Remediation
Install updates from vendor's website.