CriticalCVE-2019-1388

    Microsoft Windows Certificate Dialog Privilege Escalation Vulnerability (CVE-2019-1388)

    Published In CISA KEV since Sources: CVE.org

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    What is affected, what to do

    An elevation of privilege vulnerability exists in the Windows Certificate Dialog when it does not properly enforce user privileges, aka 'Windows Certificate Dialog Elevation of Privilege Vulnerability'.

    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 eq 7 for 32-bit Systems Service Pack 1..7 for 32-bit Systems Service Pack 1
    • Microsoft Windows eq 7 for x64-based Systems Service Pack 1..7 for x64-based Systems Service Pack 1
    • Microsoft Windows eq 8.1 for 32-bit systems..8.1 for 32-bit systems
    • Microsoft Windows eq 8.1 for x64-based systems..8.1 for x64-based systems
    • Microsoft Windows eq RT 8.1..RT 8.1
    • Microsoft Windows eq 10 for 32-bit Systems..10 for 32-bit Systems
    • Microsoft Windows eq 10 for x64-based Systems..10 for x64-based Systems
    • Microsoft Windows eq 10 Version 1607 for 32-bit Systems..10 Version 1607 for 32-bit Systems
    • Microsoft Windows eq 10 Version 1607 for x64-based Systems..10 Version 1607 for x64-based Systems
    • Microsoft Windows eq 10 Version 1709 for 32-bit Systems..10 Version 1709 for 32-bit Systems
    • Microsoft Windows eq 10 Version 1709 for x64-based Systems..10 Version 1709 for x64-based Systems
    • Microsoft Windows eq 10 Version 1803 for 32-bit Systems..10 Version 1803 for 32-bit Systems
    • Microsoft Windows eq 10 Version 1803 for x64-based Systems..10 Version 1803 for x64-based Systems
    • Microsoft Windows eq 10 Version 1803 for ARM64-based Systems..10 Version 1803 for ARM64-based Systems
    • Microsoft Windows eq 10 Version 1809 for 32-bit Systems..10 Version 1809 for 32-bit Systems
    • Microsoft Windows eq 10 Version 1809 for x64-based Systems..10 Version 1809 for x64-based Systems
    • Microsoft Windows eq 10 Version 1809 for ARM64-based Systems..10 Version 1809 for ARM64-based Systems
    • Microsoft Windows eq 10 Version 1709 for ARM64-based Systems..10 Version 1709 for ARM64-based Systems
    • Microsoft Windows Server eq 2008 R2 for x64-based Systems Service Pack 1 (Core installation)..2008 R2 for x64-based Systems Service Pack 1 (Core installation)
    • Microsoft Windows Server eq 2008 R2 for Itanium-Based Systems Service Pack 1..2008 R2 for Itanium-Based Systems Service Pack 1
    • Microsoft Windows Server eq 2008 R2 for x64-based Systems Service Pack 1..2008 R2 for x64-based Systems Service Pack 1
    • Microsoft Windows Server eq 2008 for 32-bit Systems Service Pack 2 (Core installation)..2008 for 32-bit Systems Service Pack 2 (Core installation)
    • Microsoft Windows Server eq 2012..2012
    • Microsoft Windows Server eq 2012 (Core installation)..2012 (Core installation)
    • Microsoft Windows Server eq 2012 R2..2012 R2
    • Microsoft Windows Server eq 2012 R2 (Core installation)..2012 R2 (Core installation)
    • Microsoft Windows Server eq 2016..2016
    • Microsoft Windows Server eq 2016 (Core installation)..2016 (Core installation)
    • Microsoft Windows Server eq version 1803 (Core Installation)..version 1803 (Core Installation)
    • Microsoft Windows Server eq 2019..2019
    • Microsoft Windows Server eq 2019 (Core installation)..2019 (Core installation)
    • Microsoft Windows Server eq 2008 for Itanium-Based Systems Service Pack 2..2008 for Itanium-Based Systems Service Pack 2
    • Microsoft Windows Server eq 2008 for 32-bit Systems Service Pack 2..2008 for 32-bit Systems Service Pack 2
    • Microsoft Windows Server eq 2008 for x64-based Systems Service Pack 2..2008 for x64-based Systems Service Pack 2
    • Microsoft Windows Server eq 2008 for x64-based Systems Service Pack 2 (Core installation)..2008 for x64-based Systems Service Pack 2 (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

    8.6 %

    EPSS score

    Moderate — model estimates 1-10% exploitation likelihood.

    Source: FIRST EPSS, percentile 95.1

    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
    236.34 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
    8.6 %
    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
    95.1
    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
    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
    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-269

    Response and mitigation

    Why act now?

    Prioritisation rationale

    Exploitation requires local, low-privileged access. In return it is trivial to execute, needs no interaction from anyone else, and yields full system compromise. That makes it a reliable post-initial-access escalation step for ransomware operators who land via phishing or stolen RDP credentials. CISA confirms ransomware campaign use, and exploitation likelihood is well above average. Rank terminal servers, VDI and kiosk estates, and legacy Windows 10 builds as high priority. Fully patched single-user workstations only need routine compliance verification.

    1. Runbook step 1

      Immediate response (0-24 h)

      • Deploy the November 2019 Patch Tuesday security updates, or any later cumulative update, to all affected Windows 10 builds (1507, 1607, 1709, 1803) and related server versions. Look up the per-build KB number in Microsoft's advisory for CVE-2019-1388. Verify compliance via WSUS, Intune or SCCM.
      • Prioritise unpatched hosts with shared interactive access: terminal servers, RDP jump hosts, VDI pools, kiosk and training PCs. Exploitation needs a GUI session, and any local account will do.
      • Treat out-of-support builds (1507, 1709, 1803) as unmaintained. Schedule an upgrade to a supported Windows release, and network-isolate those hosts until then.
      • Hunt across endpoints for the public PoC binary HHUPD.EXE (a signed installer with a certificate link). Also look for other unexpected signed installers in user profiles and %TEMP%.
      • If you find evidence of exploitation, treat the host as SYSTEM-level compromised. Rotate local admin passwords (LAPS) and cached credentials, and check for lateral movement. The CISA ransomware flag is set.

    2. Runbook step 2

      Mitigation layers

      • Access control: Use GPO to restrict "Allow log on locally" and "Allow log on through Remote Desktop Services" to the groups that need them. Do not give standard users interactive sessions on servers.
      • Application control: Use WDAC or AppLocker to block HHUPD.EXE and unapproved installers running from user-writable paths. Restrict cmd.exe and powershell.exe for standard users on kiosk and terminal hosts.
      • Endpoint hardening: Remove or disable Internet Explorer 11 as a Windows feature. The classic attack path clicks the "Issued by" link, which opens a browser window running as SYSTEM.
      • EDR rule (block mode): Kill any child process of consent.exe that is not part of the normal UAC flow (browsers, shells, Explorer).
      • Network segmentation: Force outbound HTTP/HTTPS from SYSTEM-context processes on terminal servers through a logging proxy. Move unpatched legacy hosts into a dedicated VLAN with no path to Tier-0 assets.

    3. Runbook step 3

      Detection rules

      • Sysmon EID 1 / Security 4688: Watch for the process chain consent.exe → browser (iexplore.exe, msedge.exe, chrome.exe) → cmd.exe/powershell.exe with User = NT AUTHORITY\SYSTEM. Sigma shape: ParentImage|endswith: '\consent.exe' AND Image|endswith: ['\iexplore.exe','\msedge.exe','\chrome.exe','\firefox.exe'].
      • KQL (Defender for Endpoint): DeviceProcessEvents | where InitiatingProcessFileName =~ "consent.exe" and FileName in~ ("iexplore.exe","msedge.exe","cmd.exe","powershell.exe")
      • SPL: index=sysmon EventCode=1 ParentImage="*\\consent.exe" NOT Image="*\\consent.exe" | stats count by host, Image, User
      • File and process IOC: Watch for execution of HHUPD.EXE (Sysmon EID 1, EID 11 FileCreate) outside legitimate software deployment. A SYSTEM shell then typically appears in the same user session (matching TerminalSessionId).
      • Follow-on activity: Look for new local admins (events 4720 and 4732) or new services (event 7045) shortly after a consent.exe event triggered by a standard user.

    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

    An elevation of privilege vulnerability exists in the Windows Certificate Dialog when it does not properly enforce user privileges, aka 'Windows Certificate Dialog Elevation of Privilege Vulnerability'.

    Source: NVD (NIST), cvelistv5, 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 versionsFixed in
    MicrosoftWindows
    • 10 Version 1803 for x64-based Systems
    • 10 Version 1709 for ARM64-based Systems
    • RT 8.1
    • 10 Version 1809 for ARM64-based Systems
    • 10 Version 1709 for x64-based Systems
    • 10 for 32-bit Systems
    • 10 for x64-based Systems
    • 8.1 for 32-bit systems
    • 10 Version 1803 for 32-bit Systems
    • 10 Version 1607 for 32-bit Systems
    • 7 for x64-based Systems Service Pack 1
    • 10 Version 1607 for x64-based Systems
    • 7 for 32-bit Systems Service Pack 1
    • 10 Version 1809 for x64-based Systems
    • 10 Version 1809 for 32-bit Systems
    • 8.1 for x64-based systems
    • 10 Version 1709 for 32-bit Systems
    • 10 Version 1803 for ARM64-based Systems
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    MicrosoftWindows Server
    • 2008 for Itanium-Based Systems Service Pack 2
    • 2012 R2
    • 2019
    • 2008 for x64-based Systems Service Pack 2 (Core installation)
    • 2008 R2 for x64-based Systems Service Pack 1
    • 2012 (Core installation)
    • 2008 for 32-bit Systems Service Pack 2 (Core installation)
    • 2008 for 32-bit Systems Service Pack 2
    • 2008 R2 for Itanium-Based Systems Service Pack 1
    • 2012
    • 2012 R2 (Core installation)
    • 2019 (Core installation)
    • 2008 R2 for x64-based Systems Service Pack 1 (Core installation)
    • 2016 (Core installation)
    • 2016
    • version 1803 (Core Installation)
    • 2008 for x64-based Systems Service Pack 2
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    Vendors and products

    Affected operating systems

    Affected operating systems
    Windowsmicrosoftwindows_10_1507—
    Windowsmicrosoftwindows_10_1607—
    Windowsmicrosoftwindows_10_1709—
    Windowsmicrosoftwindows_10_1803—
    Windowsmicrosoftwindows_10_1809—
    Windowsmicrosoftwindows_10_1903—
    Windowsmicrosoftwindows_7—
    Windowsmicrosoftwindows_8.1—
    Windowsmicrosoftwindows_rt_8.1—
    Windowsmicrosoftwindows_server_1903—
    Windowsmicrosoftwindows_server_2008r2
    Windowsmicrosoftwindows_server_2008—
    Windowsmicrosoftwindows_server_2012r2
    Windowsmicrosoftwindows_server_2012—
    Windowsmicrosoftwindows_server_20161803
    Windowsmicrosoftwindows_server_2016—
    Windowsmicrosoftwindows_server_2019—

    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 CatalogCISA Known Exploited Vulnerability (opens in a new tab)cisa.govactively exploited
    PoC-in-GitHub (nomi-sec)CVE-2019-1388-Privilege-Escalation--2021- (opens in a new tab)github.comPoC (publicly reported)reported, not verified

    References & sources

    • portal.msrc.microsoft.comen-US/security-guidance/advisory/CVE-2019-1388x_refsource_MISC, Patch, Vendor advisory
    • zerodayinitiative.comadvisories/ZDI-19-975x_refsource_MISC, Third-party advisory
    • cisa.govknown-exploited-vulnerabilities-catalog?field_cve=CVE-2019-1388government-resource, US government resource
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