Immediate Response Required: Windows 10/11 (CVE-2021-36934) Security Vulnerabilities
CVE-2021-36934 lets an ordinary Windows 10 or 11 user read system files and gain administrator rights. What it means for cardholder data, and how to fix it.
Microsoft Windows has recently updated, causing a high-risk Security Vulnerability (CVE-2021-36934) with a CVSS score of over 7 on July 23, 2021. This vulnerability is originated from the loose access control of files in system folders. Attackers with general user access rights are able to read important system files, obtain passwords of all users in the system, and gain administrator rights.
From testing, the devices currently affected are mainly Windows 10 and Windows 11, however from the official information released by Microsoft, versions above Windows 10 1809 are all affected.
Looking at this issue from the perspective of PCI DSS Compliance, the CVSS score of this vulnerability is 7.8 in NVD Database, which is considered a high-risk vulnerability. Merchants and service providers should treat the mitigation of this vulnerability as high priority to maintain the compliance and security of the cardholder data environment.
Secure Vectors proposes the following suggestions: restrict and verify user access on all Windows hosts in the environment; monitor the release of the official patch and complete patching within one month of release per PCI DSS Requirement 6.2; and where patching is not yet possible, apply the official workaround — restrict access to the affected files and delete Volume Shadow Copy Service (VSS) shadow copies — while assessing the impact on backup operations.
Reference: Microsoft Security Response Center — CVE-2021-36934