Microsoft Releases Patches for 74 New Vulnerabilities in August Update

A side channel vulnerability on some of the AMD CPUs may allow an attacker to influence the return address prediction. This may result in speculative execution at an attacker-controlled address, potentially leading to information disclosure.

Windows Kernel Elevation of Privilege Vulnerability

Windows Kernel Elevation of Privilege Vulnerability

Microsoft Exchange Server Remote Code Execution Vulnerability

CVE-2023-36884 is a race condition (TOCTOU) vulnerability in Microsoft Windows Search that permits remote code execution, rated 7.5 (high) on CVSS 3.1. It is triggered over the network with user interaction — for example, when a user opens or interacts with a specially crafted document that causes the vulnerable search code path to race, allowing arbitrary code execution in the context of the current user. An attacker gains code execution on the victim's Windows system, which the RomCom threat actor chained with Firefox flaws to deploy backdoors against political targets, and CISA notes known ransomware use. Virtually every supported Windows client and server release at the time is affected, spanning Windows 10 1507 through 22H2, Windows 11 21H2/22H2, and Windows Server 2008 through 2022. The flaw was actively exploited as a zero-day before being fixed in the July 2023 Patch Tuesday; it was added to the CISA KEV catalog on 2023-07-17 and carries a 98.9% EPSS score (100th percentile).

Do: Apply the July 2023 Patch Tuesday Windows security updates to all Windows 10, Windows 11, and Windows Server systems, prioritizing high-value and frequently attacked endpoints since the bug was exploited as a zero-day by RomCom and carries a KEV deadline (US civilian agencies were directed to remediate by August 1, 2023). Because exploitation requires user interaction, caution users against opening untrusted documents, and verify patch status via your patch management or vulnerability scanner against the KEV requirement. If patching is not possible, follow vendor mitigations per CISA's required action or discontinue use.

CVE-2023-38180 is a denial-of-service vulnerability in Microsoft .NET and Visual Studio 2022 caused by uncontrolled resource consumption (CWE-400). Per the CVSS vector, a remote, unauthenticated attacker can trigger it over the network with no privileges or user interaction required, causing affected applications or services to exhaust resources and become unavailable. The attacker gains only availability impact (high availability severity, no confidentiality or integrity impact), but this can take down ASP.NET Core web applications and other .NET-based services. Any organization running vulnerable .NET runtimes, ASP.NET Core applications, or Visual Studio 2022 is exposed, and Fedora also ships affected .NET packages. The flaw is being actively exploited in the wild: CISA added it to the Known Exploited Vulnerabilities catalog on 2023-08-09, it was among the two actively exploited flaws fixed in Microsoft's August 2023 Patch Tuesday, and EPSS assigns a 14.0% 30-day exploitation probability (96th percentile).

Do: Apply the August 2023 Microsoft security updates for all affected .NET, ASP.NET Core, and Visual Studio 2022 versions listed in Microsoft's advisory, and install the updated .NET packages on Fedora; because this flaw is in CISA's KEV catalog, the required action is to apply vendor mitigations or discontinue use of the product if mitigations are unavailable. After updating, rebuild or restart .NET applications so they run on the patched runtime, and monitor internet-facing .NET services for signs of resource-exhaustion denial-of-service. No public proof-of-concept is known, but active exploitation has been reported, so patching should be treated as urgent.