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Microsoft Releases May 2023 Security Updates

Scheduled updates for Microsoft products, including security updates for three zero-day vulnerabilities

Report a cyber attack: call 0300 303 5222 or email [email protected]

Summary

Scheduled updates for Microsoft products, including security updates for three zero-day vulnerabilities


The following platforms are also known to be affected:

  • Microsoft Bluetooth Driver
  • Microsoft Graphics Component
  • Microsoft Windows Codecs Library
  • Remote Desktop Client
  • SysInternals
  • Visual Studio Code
  • Windows Backup Engine
  • Windows Installer
  • Windows iSCSI Target Service
  • Windows Kernel
  • Windows LDAP - Lightweight Directory Access Protocol
  • Windows MSHTML Platform
  • Windows Network File System
  • Windows NFS Portmapper
  • Windows NTLM
  • Windows OLE
  • Windows PGM
  • Windows RDP Client
  • Windows Remote Procedure Call Runtime
  • Windows Secure Boot
  • Windows Secure Socket Tunneling Protocol (SSTP)
  • Windows SMB
  • Windows Win32K

Threat details

Introduction

Microsoft has released security updates to address 41 vulnerabilities across their products, with 6 of them rated as critical and 3 reported as zero-day vulnerabilities. An unauthenticated, remote attacker could exploit some of these vulnerabilities to take control of an affected system.

Known exploitation of CVE-2023-29336 and CVE-2023-24932

Microsoft has released updates for a zero-day vulnerability that has been added to CISA's Known Exploited Vulnerabilities Catalog. The vulnerability referred to as CVE-2023-29336 is a privilege escalation vulnerability in the Win32k Kernel driver. 

The vulnerability known as CVE-2023-24932 is a secure boot security feature bypass vulnerability, which has also been observed being actively exploited to install a malicious bootkit.

Exploitation of CVE-2023-29325 and CVE-2023-24955 more likely

Microsoft have reported that CVE-2023-29325 is more likely to be exploited. This vulnerability in Microsoft Outlook could lead to remote code execution (RCE). A remote attacker could exploit this vulnerability by sending a specially crafted email to an affected system.

A proof-of-concept has been published for the privilege escalation vulnerability CVE-2023-29357. If it was chained together with RCE vulnerability CVE-2023-24955, an attacker could combine the vulnerabilities to achieve unauthenticated remote code execution in SharePoint.


Threat updates

Date Update
3 Oct 2023 CVE-2023-24955 could be used in exploit chain with CVE-2023-29357 to achieve RCE

This cyber alert has been updated to reflect the possibility of CVE-2023-24955 being used in an exploit chain with CVE-2023-29357 to achieve unauthenticated RCE.


Remediation advice

Affected organisations are encouraged to review Microsoft’s May 2023 Security Update Summary and Deployment Information and apply the relevant updates.



Last edited: 3 October 2023 2:44 pm