Microsoft’s last Patch Tuesday for 2023 brought fixes for 33 vulnerabilities, including four critical and 29 important ones. Although none of the flaws were reported as publicly known or actively exploited, some significant issues were addressed, such as a Windows MSHTML Platform Remote Code Execution Vulnerability (CVE-2023-35628, CVSS score: 8.1) and an Internet Connection Sharing (ICS) Remote Code Execution Vulnerability (CVE-2023-35630, CVSS score: 8.8).
The critical CVE-2023-36019 (CVSS score: 9.6) is notable as it allows attackers to send a specially crafted URL to execute malicious scripts in the victim’s browser, emphasizing the importance of promptly applying patches. Additionally, three flaws in the Dynamic Host Configuration Protocol (DHCP) server service were fixed, addressing potential denial-of-service and information disclosure issues. These DHCP vulnerabilities (CVE-2023-35638, CVE-2023-35643, and CVE-2023-36012) could be exploited to varying degrees, from denial-of-service to sensitive data exposure.
The disclosure coincides with Akamai’s discovery of attacks against Active Directory domains using Microsoft Dynamic Host Configuration Protocol (DHCP) servers. These attacks could enable the spoofing of sensitive DNS records, potentially leading to credential theft or full Active Directory domain compromise. Microsoft responded to the findings by suggesting users disable DHCP DNS Dynamic Updates if not needed and avoid using DNSUpdateProxy.
Apart from Microsoft, various other vendors released security updates to address vulnerabilities in their products, emphasizing the broader need for organizations to stay vigilant and apply patches promptly across their software and systems.