CriticalCVE-2018-8405

Microsoft DirectX Graphics Kernel Privilege Escalation Vulnerability (CVE-2018-8405)

Published 15.08.2018In CISA KEV since 28.03.2022Sources: CVE.org

What is affected, what to do

An elevation of privilege vulnerability exists when the DirectX Graphics Kernel (DXGKRNL) driver improperly handles objects in memory, aka "DirectX Graphics Kernel Elevation of Privilege Vulnerability." This affects Windows Server 2012 R2, Windows RT 8.1, Windows Server 2016, Windows 8.1, Windows 10, Windows 10 Servers. This CVE ID is unique from CVE-2018-8400, CVE-2018-8401, CVE-2018-8406.

The vulnerability is being actively exploited; treat it as a priority. CISA lists it as used in ransomware campaigns. The available sources name no fixed version. Check the vendor guidance in the references below. Immediate actions, mitigation and detection rules are in the runbook below.

Affected: Microsoft Windows Server 2012 R2 eq (Server Core installation)..(Server Core installation)
Microsoft Windows RT 8.1 eq Windows RT 8.1..Windows RT 8.1
Microsoft Windows Server 2016 eq (Server Core installation)..(Server Core installation)
Microsoft Windows 8.1 eq 32-bit systems..32-bit systems
Microsoft Windows 8.1 eq x64-based systems..x64-based systems
Microsoft Windows 10 eq 32-bit Systems..32-bit Systems
Microsoft Windows 10 eq Version 1607 for 32-bit Systems..Version 1607 for 32-bit Systems
Microsoft Windows 10 eq Version 1607 for x64-based Systems..Version 1607 for x64-based Systems
Microsoft Windows 10 eq Version 1703 for 32-bit Systems..Version 1703 for 32-bit Systems
Microsoft Windows 10 eq Version 1703 for x64-based Systems..Version 1703 for x64-based Systems
Microsoft Windows 10 eq Version 1709 for 32-bit Systems..Version 1709 for 32-bit Systems
Microsoft Windows 10 eq Version 1709 for x64-based Systems..Version 1709 for x64-based Systems
Microsoft Windows 10 eq Version 1803 for 32-bit Systems..Version 1803 for 32-bit Systems
Microsoft Windows 10 eq Version 1803 for x64-based Systems..Version 1803 for x64-based Systems
Microsoft Windows 10 eq x64-based Systems..x64-based Systems
Microsoft Windows 10 Servers eq version 1709 (Server Core Installation)..version 1709 (Server Core Installation)
Microsoft Windows 10 Servers eq version 1803 (Server Core Installation)..version 1803 (Server Core Installation)

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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: CVE.org

3.4 %

EPSS score

Moderate — model estimates 1-10% exploitation likelihood.

Source: FIRST EPSS, percentile 88.9

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: 227.30 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: 3.4 %; 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: 88.9; 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: 15.08.2018
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: 28.03.2022
CISA assessment (SSVC): Exploitation: active · not automatable · Technical impact: total; Source: CISA Vulnrichment, as of 7 February 2025
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-404

Response and mitigation

Why act now?

Prioritisation rationale

This is a local privilege escalation in the DirectX graphics kernel driver. Any low-privileged foothold can become SYSTEM without user interaction, giving full control over the host's confidentiality, integrity and availability. CISA flags it as used in ransomware campaigns. In practice it is a second-stage tool after initial access (phishing, exposed RDP), used to kill EDR, dump credentials and spread laterally. Exploitation likelihood is clearly above average, though not in the top tier. Because the fix has been available since 2018, any affected host is a symptom of a broader patch-management gap. Treat affected multi-user and end-of-life systems as high priority, and well-patched fleets as a verification task only.

01
Runbook step 1
Immediate response (0-24 h)
- Scope the fleet: Identify every Windows 8.1, Windows RT 8.1, Windows Server 2012 R2, Windows Server 2016 and Windows 10 (1507, 1607, 1703, 1709) host that is below the August 2018 patch level. MDE KQL: DeviceTvmSoftwareVulnerabilities | where CveId == "CVE-2018-8405". Alternatively, filter WSUS/SCCM/Intune compliance reports for the missing cumulative update.
- Patch: Install the Microsoft security fix for CVE-2018-8405. It ships in the August 2018 Patch Tuesday release and in every later cumulative update or monthly rollup. Look up the per-build KB number in the Microsoft Security Update Guide. Force the reboot, because the fix replaces the kernel driver dxgkrnl.sys.
- Handle end-of-life builds: Windows 10 1507 to 1709 and Server 2012 R2 without ESU no longer receive updates. Tag these as high-risk assets and schedule migration or isolation. A host missing this fix is almost certainly missing other kernel EoP fixes too.
- Patch multi-user exposure first: Start with RDS/terminal servers, Citrix hosts, jump servers and VDI pools, then any system with many low-privileged interactive users. Exploitation requires local code execution.
- Check for compromise: On unpatched hosts with recent malware alerts, hunt for unexpected SYSTEM processes (see Detection rules). If you get hits, isolate the host and rotate any privileged credentials cached on it.
02
Runbook step 2
Mitigation layers
- Application control: Enforce a WDAC or AppLocker policy that blocks execution from user-writable paths (%USERPROFILE%, %TEMP%, %APPDATA%, C:\Users\Public). Exploits for this flaw are usually dropped as standalone binaries or reflectively loaded. Microsoft lists no official workaround, and the vendor advisory provides no configuration bypass.
- Endpoint hardening: Set these Defender ASR rules to block mode:
  
  "Block executable files unless they meet prevalence, age or trusted list criterion"
  
  "Block process creations originating from PSExec and WMI commands"
  
  Also enable EDR Tamper Protection, since ransomware operators disable security tooling as soon as they reach SYSTEM.
- IAM and least privilege: Restrict interactive and RDP logon rights on servers to admin groups (SeRemoteInteractiveLogonRight, SeInteractiveLogonRight). Enforce admin tiering so Tier-0 accounts never log on to exposed clients. This limits what a successful local escalation can harvest.
- Credential protection: Enable Credential Guard and LSA protection (RunAsPPL), and deploy LAPS for unique local admin passwords. This breaks the common "SYSTEM → LSASS dump → lateral movement" chain.
- Network segmentation: Move unpatchable legacy systems into a dedicated VLAN. Block outbound SMB, RDP and WinRM (445, 3389, 5985/5986) from that VLAN to other segments, allowing only designated management hosts.
03
Runbook step 3
Detection rules
- SYSTEM child from a user-context parent (Sysmon EID 1 / Security 4688): Alert when a process runs as SYSTEM but its parent runs as a standard user. KQL: DeviceProcessEvents | where AccountSid == "S-1-5-18" and InitiatingProcessAccountSid !in ("S-1-5-18","S-1-5-19","S-1-5-20") and FileName in~ ("cmd.exe","powershell.exe","rundll32.exe").
- Kernel instability: On unpatched hosts, bugchecks referencing dxgkrnl.sys (System event 1001 BugCheck, event 41 Kernel-Power) can indicate failed exploitation attempts. Correlate them with minidump analysis.
- Suspicious dropped binaries: Use Sysmon EID 11 and EID 1 to catch new unsigned EXEs in \AppData\Local\Temp\ or \Users\Public\ that are executed shortly after creation. Sigma shape: Image|contains: '\Temp\' AND Signed: false AND IntegrityLevel: System.
- Post-escalation behaviour: Watch for vssadmin delete shadows, wbadmin delete catalog, bcdedit /set recoveryenabled no, and LSASS access (Sysmon EID 10, TargetImage ending in lsass.exe, GrantedAccess 0x1010/0x1FFFFF). This chain is a strong ransomware precursor.
- AV/EDR signatures: Merge Defender or EDR alerts that reference CVE-2018-8405, or generic kernel-EoP "Win32/Exploit" detections, with any subsequent SYSTEM shell on the same host into a single incident.

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

Source: NVD (NIST), cvelistv5, CISA KEV Catalog

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	`32-bit Systems` `Version 1803 for 32-bit Systems` `x64-based Systems` `Version 1703 for 32-bit Systems` `Version 1709 for 32-bit Systems` `Version 1803 for x64-based Systems` `Version 1607 for 32-bit Systems` `Version 1703 for x64-based Systems` `Version 1709 for x64-based Systems` `Version 1607 for x64-based Systems`	— — — — — — — — — —
Microsoft	Windows 10 Servers	`version 1803 (Server Core Installation)` `version 1709 (Server Core Installation)`	— —
Microsoft	Windows 8.1	`x64-based systems` `32-bit systems`	— —
Microsoft	Windows RT 8.1	`Windows RT 8.1`	—
Microsoft	Windows Server 2012 R2	`(Server Core installation)`	—
Microsoft	Windows Server 2016	`(Server Core installation)`	—

Vendors and products

Affected operating systems

Affected operating systems

Windows	microsoft	windows_10_1507	—
Windows	microsoft	windows_10_1607	—
Windows	microsoft	windows_10_1703	—
Windows	microsoft	windows_10_1709	—
Windows	microsoft	windows_10_1803	—
Windows	microsoft	windows_8.1	—
Windows	microsoft	windows_rt_8.1	—
Windows	microsoft	windows_server_1709	—
Windows	microsoft	windows_server_1803	—
Windows	microsoft	windows_server_2012	`r2`
Windows	microsoft	windows_server_2016	—

Weakness classes (CWE)

CWE-404Improper Resource Shutdown or Release
Class
The product does not release or incorrectly releases a resource before it is made available for re-use.
Entry at MITRE CWE-404

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	28.03.2022

References & sources

securityfocus.com105011Vulnerability database, x_refsource_BID, Broken link, Third-party advisory, Vulnerability database
securitytracker.com1041461Vulnerability database, x_refsource_SECTRACK, Broken link, Third-party advisory, Vulnerability database
portal.msrc.microsoft.comen-US/security-guidance/advisory/CVE-2018-8405x_refsource_CONFIRM, Patch, Vendor advisory
cisa.govknown-exploited-vulnerabilities-catalog?field_cve=CVE-2018-8405government-resource, US government resource

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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