CVE-2023-21674: 
vulnerability analysis and mitigation

CVE-2023-21674 is a Windows Advanced Local Procedure Call (ALPC) Elevation of Privilege Vulnerability discovered and disclosed in January 2023. This vulnerability affects a wide variety of Windows and Windows Server installations, allowing attackers to perform privilege escalation to gain SYSTEM-level access (HelpNet Security).

The vulnerability has been assigned a CVSS v3.1 base score of 8.8 (HIGH) with the vector string CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H. It is classified as a Use After Free (CWE-416) vulnerability that could lead to a browser sandbox escape. The vulnerability requires local access and low attack complexity to exploit (NVD).

If successfully exploited, this vulnerability enables attackers to escape browser sandbox restrictions and elevate their privileges to SYSTEM level on affected systems. The vulnerability is particularly concerning as it can be paired with code execution techniques to deliver malware or ransomware (HelpNet Security).

Microsoft has released security updates to address this vulnerability. Organizations are advised to apply the relevant patches immediately through Windows Update. The vulnerability was included in Microsoft's January 2023 Patch Tuesday updates, and CISA has added it to their Known Exploited Vulnerabilities Catalog with a remediation date of January 31, 2023 (NVD).