CriticalCVE-2024-26169

Windows Error Reporting Service Elevation of Privilege Vulnerability (CVE-2024-26169)

Published 12.03.2024In CISA KEV since 13.06.2024Sources: pwn.watch, CVE.org

What is affected, what to do

Windows Error Reporting Service Elevation of Privilege Vulnerability

The vulnerability is being actively exploited; treat it as a priority. CISA lists it as used in ransomware campaigns. Update Microsoft Windows 10 Version 1809 to version 10.0.17763.5576, Microsoft Windows Server 2019 to version 10.0.17763.5576, Microsoft Windows Server 2019 (Server Core installation) to version 10.0.17763.5576. Immediate actions, mitigation and detection rules are in the runbook below.

Affected: Microsoft Windows 10 Version 1809 lt 10.0.17763.0..10.0.17763.5576
Microsoft Windows Server 2019 lt 10.0.17763.0..10.0.17763.5576
Microsoft Windows Server 2019 (Server Core installation) lt 10.0.17763.0..10.0.17763.5576
Microsoft Windows Server 2022 lt 10.0.20348.0..10.0.20348.2340
Microsoft Windows 11 version 21H2 lt 10.0.0..10.0.22000.2836
Microsoft Windows 10 Version 21H2 lt 10.0.19043.0..10.0.19044.4170
Microsoft Windows 11 version 22H2 lt 10.0.22621.0..10.0.22621.3296
Microsoft Windows 10 Version 22H2 lt 10.0.19045.0..10.0.19045.4170
Microsoft Windows 11 version 22H3 lt 10.0.22631.0..10.0.22631.3296
Microsoft Windows 11 Version 23H2 lt 10.0.22631.0..10.0.22631.3296
Microsoft Windows Server 2022, 23H2 Edition (Server Core installation) lt 10.0.25398.0..10.0.25398.763
Microsoft Windows 10 Version 1507 lt 10.0.10240.0..10.0.10240.20526
Microsoft Windows 10 Version 1607 lt 10.0.14393.0..10.0.14393.6796
Microsoft Windows Server 2016 lt 10.0.14393.0..10.0.14393.6796
Microsoft Windows Server 2016 (Server Core installation) lt 10.0.14393.0..10.0.14393.6796
Microsoft Windows Server 2012 R2 lt 6.3.9600.0..6.3.9600.21871
Microsoft Windows Server 2012 R2 (Server Core installation) lt 6.3.9600.0..6.3.9600.21871
Fixed in: Microsoft Windows 10 Version 1809 10.0.17763.5576
Microsoft Windows Server 2019 10.0.17763.5576
Microsoft Windows Server 2019 (Server Core installation) 10.0.17763.5576
Microsoft Windows Server 2022 10.0.20348.2340
Microsoft Windows 11 version 21H2 10.0.22000.2836
Microsoft Windows 10 Version 21H2 10.0.19044.4170
Microsoft Windows 11 version 22H2 10.0.22621.3296
Microsoft Windows 10 Version 22H2 10.0.19045.4170
Microsoft Windows 11 version 22H3 10.0.22631.3296
Microsoft Windows 11 Version 23H2 10.0.22631.3296
Microsoft Windows Server 2022, 23H2 Edition (Server Core installation) 10.0.25398.763
Microsoft Windows 10 Version 1507 10.0.10240.20526
Microsoft Windows 10 Version 1607 10.0.14393.6796
Microsoft Windows Server 2016 10.0.14393.6796
Microsoft Windows Server 2016 (Server Core installation) 10.0.14393.6796
Microsoft Windows Server 2012 R2 6.3.9600.21871
Microsoft Windows Server 2012 R2 (Server Core installation) 6.3.9600.21871

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Metrics

7.8

Priority

XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.

Source: NVD, CVSS v3

7.8

CVSS v3

Severity High on the scale from 0 to 10.

Source: pwn.watch, CVE.org

4.0 %

EPSS score

Moderate — model estimates 1-10% exploitation likelihood.

Source: FIRST EPSS, percentile 90.6

Show all metrics

Severity: Critical
Priority (0–325) The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first? Read in glossary: 234.30 Methodology
Exploit maturity An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack. Read in glossary: actively exploited
XIEM Effective CVSS XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command. Read in glossary: 7.8 Methodology
CVSS v3 CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions. Read in glossary: 7.8
EPSS score The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“. Read in glossary: 4.0 %; Moderate — model estimates 1-10% exploitation likelihood.
EPSS percentile The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking. Read in glossary: 90.6; Critical — this CVE ranks in the top fifth of all CVEs scored today (rank ≥ 80%).
KEV status The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching. Read in glossary: Actively exploited
Published: 12.03.2024
In CISA KEV since The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching. Read in glossary: 13.06.2024
CISA assessment (SSVC): Exploitation: active · not automatable · Technical impact: total; Source: CISA Vulnrichment, as of 14 June 2024
CWE CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect. Read in glossary: CWE-269

Response and mitigation

Why act now?

Prioritisation rationale

This CVE sits on KEV because it has been observed as the second stage of ransomware intrusions: operators gain an initial foothold through phishing or an initial-access broker, then use CVE-2024-26169 to jump from a standard user context to SYSTEM without needing additional credentials, disable EDR, and detonate ransomware. Local-only attack vectors look harmless on paper, but exploitation is trivially reproducible, needs no user interaction, and hides inside a signed Windows service that most baselines whitelist. Prioritise patching by host exposure: multi-user systems (Citrix, RDS, VDI, developer workstations) and any endpoint with internet-facing user activity go first; isolated single-user appliances last. For NIS2-regulated organisations this belongs in the top patch class with an SLA of 7 days or less, especially if initial-access indicators (phishing clicks, suspicious OAuth grants) have already been seen on the estate.

01
Runbook step 1
Immediate response (0-24 h)
- Deploy the Microsoft March 2024 Patch Tuesday update for CVE-2024-26169 (look up the per-build KB IDs in the MSRC advisory) via WSUS/Intune/SCCM across all Windows 10 branches 1507, 1607, 1809, 21H2 and 22H2. Target builds are at minimum 10.0.19045.4170 (22H2), 10.0.17763.5576 (1809), 10.0.14393.6796 (1607) and 10.0.10240.20526 (1507).
- Patch terminal servers, VDI pools, jump hosts and developer workstations first — any system with concurrent interactive users is a primary target, because the flaw escalates an already authenticated local user straight to SYSTEM.
- Hunt for WerFault.exe or WerFaultSecure.exe spawning unexpected child processes (cmd.exe, powershell.exe, rundll32.exe); isolate matching hosts and triage forensically before patching, so you do not overwrite evidence.
- On legacy hosts that cannot be patched quickly (e.g. OT/HMI systems still on 1607 LTSB), temporarily strip local admin rights and block interactive logons for standard users until the vendor update lands.
- Secure a CAB emergency-change exception and document the rollout against the NIS2 24 h early-warning window in case exploitation indicators surface during the campaign.
02
Runbook step 2
Mitigation layers
- Endpoint hardening: enable the ASR rules "Block abuse of exploited vulnerable signed drivers" and "Block process creations originating from PSExec and WMI commands" in enforce mode; use WDAC/AppLocker to block werfault.exe from being the parent of shell or scripting interpreters.
- IAM / least privilege: cut local admin rights on workstations to the bare minimum using LAPS and just-in-time elevation (PIM / EPM); separate developer and admin accounts into distinct tiers aligned with the Microsoft Enterprise Access Model.
- Configuration monitoring: watch HKLM\SOFTWARE\Microsoft\Windows\Windows Error Reporting for unexpected sub-key creation and impersonation-style registry writes; public PoCs typically drop artefacts under C:\ProgramData\Microsoft\Windows\WER\ERC.
- Network segmentation: constrain lateral movement after a successful LPE by host-firewall rules blocking SMB (445), RPC (135) and WinRM (5985/5986) between client subnets; only permit traffic from dedicated admin jump hosts.
- EDR posture: enable LSASS Protected Process Light and Credential Guard so that a SYSTEM-level foothold does not translate trivially into NTLM hashes and Kerberos tickets usable for lateral movement.
- Resilience: because KEV flags this CVE as used in ransomware campaigns, verify offline / immutable backups of critical file shares and domain controller snapshots, and rehearse restore timings.
03
Runbook step 3
Detection rules
- Sysmon EID 1: alert when werfault.exe or wermgr.exe is the parent of an interpreter. Sigma shape: parent_image endswith '\WerFault.exe' AND image in ('\cmd.exe','\powershell.exe','\pwsh.exe','\wscript.exe','\cscript.exe','\rundll32.exe').
- Sysmon EID 11/15: suspicious file writes under C:\ProgramData\Microsoft\Windows\WER\ERC\ or new .exe/.dll files in %TEMP% that are loaded shortly afterwards by WerFault; correlate with EID 7 image loads of unsigned modules from WER paths.
- Windows Security 4688 with command-line auditing enabled: New Process Name ending in WerFault.exe with TokenElevationType = TokenElevationTypeFull (%%1936) where the invoking user SID was a standard account.
- KQL for Microsoft Defender for Endpoint: DeviceProcessEvents | where InitiatingProcessFileName in~ ("werfault.exe","wermgr.exe") | where FileName in~ ("cmd.exe","powershell.exe","pwsh.exe","rundll32.exe") | where InitiatingProcessIntegrityLevel == "System" and AccountName !in ("SYSTEM","LOCAL SERVICE","NETWORK SERVICE").
- Registry monitoring (Sysmon EID 12/13): changes to HKLM\SOFTWARE\Microsoft\Windows\Windows Error Reporting\Hangs or creation of a "Debugger" value in Image File Execution Options-style paths by non-privileged processes.

Detection rules

No NEOSEC detection rule is available for this vulnerability yet.

Classification under NIS2 and CRA

Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.

NIS2 NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management. Read in glossary: Actively exploited: treat the vulnerability as a priority in vulnerability handling under Art. 21(2)(e) NIS2. If it is exploited in your environment, check the reporting obligation under Art. 23 (early warning within 24 hours).
CRA The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates. Read in glossary: Since 11.09.2026, manufacturers of affected products with digital elements must report actively exploited vulnerabilities under Art. 14 CRA, with an early warning within 24 hours via ENISA's single reporting platform.
ISO/IEC 27001 ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security. Read in glossary: Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.

Description

Windows Error Reporting Service Elevation of Privilege Vulnerability

Source: pwn.watch, cvelistv5, NVD (NIST), CISA KEV Catalog, CVE.org (MITRE)

Affected products

The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

Affected products
		Affected versions	Fixed in
Microsoft	Windows 10 Version 1507	`10.0.10240.0 – < 10.0.10240.20526`	`10.0.10240.20526`
Microsoft	Windows 10 Version 1607	`10.0.14393.0 – < 10.0.14393.6796`	`10.0.14393.6796`
Microsoft	Windows 10 Version 1809	`10.0.17763.0 – < 10.0.17763.5576`	`10.0.17763.5576`
Microsoft	Windows 10 Version 21H2	`10.0.19043.0 – < 10.0.19044.4170`	`10.0.19044.4170`
Microsoft	Windows 10 Version 22H2	`10.0.19045.0 – < 10.0.19045.4170`	`10.0.19045.4170`
Microsoft	Windows 11 version 21H2	`10.0.0 – < 10.0.22000.2836`	`10.0.22000.2836`
Microsoft	Windows 11 version 22H2	`10.0.22621.0 – < 10.0.22621.3296`	`10.0.22621.3296`
Microsoft	Windows 11 version 22H3	`10.0.22631.0 – < 10.0.22631.3296`	`10.0.22631.3296`
Microsoft	Windows 11 Version 23H2	`10.0.22631.0 – < 10.0.22631.3296`	`10.0.22631.3296`
Microsoft	Windows Server 2012 R2	`6.3.9600.0 – < 6.3.9600.21871`	`6.3.9600.21871`
Microsoft	Windows Server 2012 R2 (Server Core installation)	`6.3.9600.0 – < 6.3.9600.21871`	`6.3.9600.21871`
Microsoft	Windows Server 2016	`10.0.14393.0 – < 10.0.14393.6796`	`10.0.14393.6796`
Microsoft	Windows Server 2016 (Server Core installation)	`10.0.14393.0 – < 10.0.14393.6796`	`10.0.14393.6796`
Microsoft	Windows Server 2019	`10.0.17763.0 – < 10.0.17763.5576`	`10.0.17763.5576`
Microsoft	Windows Server 2019 (Server Core installation)	`10.0.17763.0 – < 10.0.17763.5576`	`10.0.17763.5576`
Microsoft	Windows Server 2022	`10.0.20348.0 – < 10.0.20348.2340`	`10.0.20348.2340`
Microsoft	Windows Server 2022, 23H2 Edition (Server Core installation)	`10.0.25398.0 – < 10.0.25398.763`	`10.0.25398.763`

Vendors and products

Affected operating systems

Affected operating systems

Windows	microsoft	windows_10_1507	—
Windows	microsoft	windows_10_1607	—
Windows	microsoft	windows_10_1809	—
Windows	microsoft	windows_10_21h2	—
Windows	microsoft	windows_10_22h2	—
Windows	microsoft	windows_11_21h2	—
Windows	microsoft	windows_11_22h2	—
Windows	microsoft	windows_11_23h2	—
Windows	microsoft	windows_server_2008	`r2`
Windows	microsoft	windows_server_2008	—
Windows	microsoft	windows_server_2012	`r2`
Windows	microsoft	windows_server_2016	—
Windows	microsoft	windows_server_2019	—
Windows	microsoft	windows_server_2022	—
Windows	microsoft	windows_server_2022_23h2	—

Weakness classes (CWE)

CWE-269Improper Privilege Management
Class
The product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor.
Entry at MITRE CWE-269

Public exploit references

Publicly reported proof-of-concepts, exploit modules and detection templates for this vulnerability. NEOSEC links to the original sources only and does not provide any exploit code.

Public exploit references

CISA KEV Catalog	CISA Known Exploited Vulnerability (opens in a new tab)cisa.gov	actively exploited	13.06.2024

References & sources

Microsoft Security Update GuideWindows Error Reporting Service Elevation of Privilege VulnerabilityVendor advisory, Patch, Vendor advisory, pwn-watch
cisa.govknown-exploited-vulnerabilities-catalog?field_cve=CVE-2024-26169government-resource, US government resource
pwn.watchpwn.watch: Microsoft Windows Error Reporting Service Improper Privilege Managementpwn-watch
NVD (NIST)NVD: CVE-2024-26169pwn-watch
cisa.govCISA Known Exploited Vulnerabilities Catalogpwn-watch

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<a href="https://intel.neosec.eu/en/cve/CVE-2024-26169"><img src="https://intel.neosec.eu/badge/cve/CVE-2024-26169.svg?lang=en" alt="CVE-2024-26169 – NEOSEC Intel" height="20"></a>

What is affected, what to do

Metrics

Response and mitigation

Prioritisation rationale

Immediate response (0-24 h)

Mitigation layers

Detection rules

Detection rules

Classification under NIS2 and CRA

Description

Affected products

Vendors and products

Affected operating systems

Weakness classes (CWE)

Public exploit references

References & sources