CVE-2023-23376: 
vulnerability analysis and mitigation

CVE-2023-23376 is a Windows Common Log File System (CLFS) Driver Elevation of Privilege vulnerability discovered as a zero-day in the wild by the Microsoft Threat Intelligence Center (MSTIC) and the Microsoft Security Response Center (MSRC). The vulnerability was disclosed and patched in February 2023 (Securelist, HelpNet Security).

The vulnerability exists in the Windows Common Log File System Driver and is related to the CLFSCONTROLRECORD structure. The root cause involves improper validation of iExtendBlock and iFlushBlock indexes in the ExtendMetadataBlock function, which could allow an attacker to pass an arbitrary address as a pointer to a block. The vulnerability has a CVSS v3.1 base score of 7.8 (High) with the vector string CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (NVD).

When successfully exploited, this vulnerability allows an attacker to achieve SYSTEM privileges on a target host. This elevation of privilege vulnerability is particularly concerning as it could be chained with remote code execution bugs to spread malware or ransomware (HelpNet Security).

Microsoft has released security updates to address this vulnerability. Organizations are advised to apply the patches quickly, particularly given its active exploitation in the wild. The vulnerability was added to CISA's Known Exploited Vulnerabilities Catalog with a remediation date of March 7, 2023 (NVD).