Welcome to Patch Tuesday, October 2020. This month, Microsoft has patched 87 vulnerabilities with 11 of these vulnerabilities deemed as Critical by Microsoft. Six vulnerabilities were publicly disclosed prior to patching, but have not been exploited in the wild yet.
The Windows kernel received a patch for a number of issues, two of which were publicly disclosed prior to patching. The publicly disclosed vulnerabilities allowed for sensitive information that could be leveraged by an attacker to be leaked from kernel memory. Microsoft has rated these vulnerabilities as Important to patch.
The .NET Framework for applications received numerous fixes this month and was vulnerable to an information disclosure vulnerability that was publicly disclosed prior to patching. Microsoft has rated this as Important to patch.
Numerous subcomponents of Windows received patches for vulnerabilities that were publicly disclosed prior to patching. Windows Error Reporting, Windows Setup, and Windows Storage VSP Driver were all vulnerable to Elevation of Privilege vulnerabilities that were disclosed prior to patching. Microsoft has rated these vulnerabilities as Important to patch.
The Windows TCP/IP Stack was vulnerable to an RCE problem when sent a malicious ICMPv6 router advertisement. This would result in an attacker gaining elevated privileges remotely with no user interaction. The CVSS score for this vulnerability was 9.8 / 10, with Microsoft claiming the vulnerability was very likely to be exploited. This vulnerability is considered Critical to patch.
Microsoft Outlook was vulnerable to an RCE vulnerability in its preview pane. Since the preview pane was the attack vector, the email does not need to be opened for this attack to succeed. The attack would execute code in the security context of the current user. This is another reminder why it’s imperative for everyone to exercise the principle of least privilege.
Hyper-V was susceptible to a vulnerability that allowed a guest OS to execute arbitrary code on the host OS. Attackers would have system privileges on the host, making this vulnerability extremely devastating if executed in cloud environments. This vulnerability was rated as Critical to patch by Microsoft.
SharePoint was vulnerable to two different severe vulnerabilities in the application package validation. Both vulnerabilities would be exploited by sending a maliciously crafted application package that would bypass validation and run arbitrary code as the application pool or server farm account.