Windows Error Reporting

Winsage
March 4, 2026
A proof-of-concept exploit for CVE-2026-20817, a local privilege escalation vulnerability in the Windows Error Reporting (WER) service, has been released by security researcher oxfemale on GitHub. This vulnerability allows low-privileged users to gain SYSTEM-level access through crafted Advanced Local Procedure Call (ALPC) messages. The flaw is located in the WER service's SvcElevatedLaunch method, which fails to validate caller privileges before executing WerFault.exe with user-supplied command line parameters. The CVSS v3.1 base score for this vulnerability is 7.8, indicating a high severity level. It affects unpatched versions of Windows 10, Windows 11, Windows Server 2019, and Windows Server 2022 prior to the January 2026 update. Demonstrations have shown successful exploitation on Windows 11 23H2. Security teams are advised to monitor for unusual processes related to WerFault.exe, investigate missing SeTcbPrivilege in SYSTEM tokens, and review WER-related activities from low-privilege users. Immediate application of the January 2026 security patches is recommended, and a temporary workaround involves disabling the WER service.
Winsage
March 3, 2026
A critical local privilege escalation vulnerability, tracked as CVE-2026-20817, affects Microsoft Windows through the Windows Error Reporting (WER) service. This flaw allows authenticated users with low-level privileges to execute arbitrary code with full SYSTEM privileges. The vulnerability resides in the SvcElevatedLaunch method (0x0D) and fails to validate user permissions, enabling attackers to launch WerFault.exe with malicious command-line parameters from a shared memory block. The exploit affects all versions of Windows 10 and Windows 11 prior to January 2026, as well as Windows Server 2019 and 2022. Microsoft addressed this vulnerability in the January 2026 Security Update. Organizations are advised to apply security patches and monitor for unusual WerFault.exe processes.
Winsage
February 27, 2026
Windows 10 was released in 2015 and faced criticism for its telemetry feature, which some viewed as a surveillance tool. In 2017, the Dutch Data Protection Authority found Microsoft's telemetry settings non-compliant with local privacy laws, leading to changes by Microsoft. Telemetry, termed diagnostic data by Microsoft, is essential for device reliability and security, with a baseline level of data collection set to "Required." Users can opt to limit data collection to this level. The Optional category of diagnostic data may include device settings and browsing history, raising privacy concerns. Microsoft introduced the Diagnostic Data Viewer in 2018 to enhance transparency, allowing users to inspect the telemetry data sent to them. As of now, Microsoft has over a billion monthly active Windows 11 users.
Winsage
January 13, 2026
Microsoft's January 2026 Patch Tuesday update, KB5074109, addresses 114 vulnerabilities, including a critical zero-day vulnerability (CVE-2026-20805) in the Windows Desktop Window Manager (DWM) that has been actively exploited. The update is applicable to Windows 11 versions 24H2 and 25H2 and includes security enhancements and updates to AI components. Other high-severity vulnerabilities addressed include CVE-2026-20816 (privilege escalation in Windows Installer), CVE-2026-20817 (elevation of privilege in Windows Error Reporting), CVE-2026-20840 (vulnerability in Windows NTFS), CVE-2026-20843 (flaw in Routing and Remote Access Service), CVE-2026-20860 (vulnerability in Ancillary Function Driver for WinSock), and CVE-2026-20871 (another DWM vulnerability). The update removes legacy modem drivers to minimize the attack surface and resolves reliability issues in Azure Virtual Desktop and WSL networking. It also changes the default setting for Windows Deployment Services (WDS) to disable hands-free deployment. Users can install the update through Windows Update, and a system reboot is required for full application.
Tech Optimizer
September 24, 2025
Endpoint detection and response (EDR) systems and antivirus protections are increasingly targeted by threat actors using sophisticated techniques. A new method called EDR-Freeze has been introduced, which utilizes Windows Error Reporting and the MiniDumpWriteDump function to hibernate antivirus processes without needing to install vulnerable drivers. This technique operates entirely in user mode and was disclosed by an anonymous researcher known as Two One Seven Three on Zero Salarium. The MiniDumpWriteDump function can suspend all threads within a target process during the dump process, which is crucial to avoid memory corruption. The researcher faced challenges with the rapid execution of MiniDumpWriteDump and the security measures protecting EDR and antivirus processes. By reverse-engineering the WerFaultSecure program, the researcher enabled MiniDumpWriteDump for any chosen process and integrated it with the CreateProcessAsPPL tool to bypass Protected Process Light (PPL) protections. The researcher proposed a race condition attack consisting of four steps: executing WerFaultSecure with WinTCB-level protection, configuring it to dump the target process, monitoring the target process until it is suspended, and then suspending the WerFaultSecure process. A tool to execute this exploit is available on GitHub, and another researcher has developed a KQL rule for its detection. The EDR-Freeze technique exploits a vulnerability in the WerFaultSecure program, addressing the weaknesses of the BYOVD method and allowing flexible control over EDR and antivirus programs.
Winsage
September 22, 2025
A new technique called EDR-Freeze allows evasion of security solutions through Microsoft's Windows Error Reporting (WER) system, enabling attackers to suspend endpoint detection and response (EDR) tools without relying on vulnerable drivers. Security researcher TwoSevenOneThree utilized the WER framework and the MiniDumpWriteDump API to indefinitely suspend EDR and antivirus processes by exploiting the WerFaultSecure component, which operates with Protected Process Light (PPL) privileges. The method involves spawning WerFaultSecure, invoking MiniDumpWriteDump on the target process, monitoring the target until it is suspended, and then freezing the dumper. A tool has been developed to automate this process, successfully tested on Windows 11 24H2, which froze the Windows Defender process. To mitigate this attack, monitoring WER for identifiers linked to sensitive processes is recommended, and security researcher Steven Lim has created a tool to map WerFaultSecure to Microsoft Defender Endpoint processes. Microsoft has the opportunity to enhance these components against misuse by implementing restrictions on suspicious invocations.
Tech Optimizer
September 22, 2025
A security researcher has developed a tool called EDR-Freeze that allows for the temporary disabling of endpoint detection and response (EDR) systems and antivirus software without using vulnerable drivers. EDR-Freeze exploits the Windows Error Reporting functionality to execute a race condition attack that suspends security processes, specifically targeting the WerFaultSecure.exe process. The tool can successfully suspend the MsMpEng.exe process of Windows Defender on Windows 11 24H2. It operates entirely within user-mode and uses legitimate Windows components, making detection more difficult for security teams. The source code for EDR-Freeze is publicly available on GitHub, intended for legitimate security research, but poses risks of misuse by malicious actors. Security teams are advised to monitor for suspicious activity related to WerFaultSecure.exe and to enhance their process protection mechanisms.
Tech Optimizer
September 21, 2025
EDR-Freeze is a proof-of-concept tool developed by Zero Salarium that can place Endpoint Detection and Response (EDR) and antivirus solutions into a suspended state. It utilizes the MiniDumpWriteDump function from the Windows DbgHelp library to achieve this by extending the suspension of target processes. The tool circumvents the Protected Process Light (PPL) security feature using WerFaultSecure.exe, which operates at a high privilege level. By launching WerFaultSecure.exe with specific parameters, EDR-Freeze can monitor and suspend it, preventing the target EDR or antivirus process from resuming. A test on Windows 11 24H2 successfully suspended the MsMpEng.exe process of Windows Defender. Detecting this technique involves monitoring for unusual executions of WerFaultSecure.exe targeting sensitive process IDs.
Winsage
April 16, 2025
Windows operating systems have numerous background services that can consume system resources and slow down performance. Users can improve responsiveness by disabling non-essential services. 1. Windows Search: Indexes files and data for quick searches; can tax CPU and RAM. To disable: press Ctrl + R, type services.msc, locate Windows Search, stop the service, and set Startup type to Disabled or Manual. 2. SysMain (formerly Superfetch): Preloads frequently used applications into memory but can lead to unnecessary disk activity on SSDs. To disable: access services.msc, find SysMain, stop the service, and set Startup Type to Disabled. 3. Windows Update Delivery Optimization: Shares update files with other PCs, consuming bandwidth. To disable: go to Settings -> Windows Update -> Advanced Options and turn it off. 4. Remote Desktop Services: Enables remote connections, which can drain resources and pose security risks. To disable: locate Remote Desktop Services in services.msc, stop it, and set Startup type to Disabled. 5. Connected User Experiences and Telemetry: Collects usage data and can transmit sensitive information. To disable: turn off the service and navigate to Settings -> Privacy & Security -> Diagnostics & Feedback to disable Diagnostic data. Additional services that may be disabled include Print Spooler, Fax, Bluetooth Support, and Windows Error Reporting Service for further performance optimization.
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