Evidence used
- No CISA KEV confirmation is currently recorded.
- EPSS is 3.49% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2018
CVE-2018-8434High confidence
Microsoft Windows 7: Improper Input Validation
Microsoft · Windows 7
5.4MediumCVSS 3.0
Scheduled
Patch availableMedium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityMedium→Operational priority:Medium, unchanged from published severity.unchanged
Compensating controls
- Validate the affected product branch and deploy the verified fixed release.
- Restrict local access and enforce least privilege on affected hosts.
- Monitor vendor guidance and exploitation sources for a material change.
Verification
- Confirm that the asset runs Microsoft Windows 7 and falls inside the recorded affected range.
- Verify the installed build against the product-specific fixed version after deployment.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.
Patch available01
What, why and how
An information disclosure vulnerability exists when Windows Hyper-V on a host operating system fails to properly validate input from an authenticated user on a guest operating system, aka "Windows Hyper-V Information Disclosure Vulnerability." This affects Windows 7, Windows Server 2012 R2, Windows RT 8.1, Windows Server 2008, Windows Server 2012, Windows 8.1, Windows Server 2016, Windows Server 2008 R2, Windows 10, Windows 10 Servers.
What
An information disclosure vulnerability exists when Windows Hyper-V on a host operating system fails to properly validate input from an authenticated user on a guest operating system, aka "Windows Hyper-V Information Disclosure Vulnerability." This affects Windows 7, Windows Server 2012 R2, Windows RT 8.1, Windows Server 2008, Windows Server 2012, Windows 8.1, Windows Server 2016, Windows Server 2008 R2, Windows 10, Windows 10 Servers.
Why
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
How
An attacker operating through the affected interface may attempt exploitation with elevated privileges. If successful, the issue may obtain information outside the intended access boundary.
What
An information disclosure vulnerability exists when Windows Hyper-V on a host operating system fails to properly validate input from an authenticated user on a guest operating system, aka "Windows Hyper-V Information Disclosure Vulnerability." This affects Windows 7, Windows Server 2012 R2, Windows RT 8.1, Windows Server 2008, Windows Server 2012, Windows 8.1, Windows Server 2016, Windows Server 2008 R2, Windows 10, Windows 10 Servers.
Why
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
How
An attacker operating through the affected interface may attempt exploitation with elevated privileges. If successful, the issue may obtain information outside the intended access boundary.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
Public PoC / exploit material None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
- Likely attack path
- the affected interface → Improper Input Validation → obtain information outside the intended access boundary
- Attack surface
- Unspecified
- Privileges required
- High: elevated access is required
- User interaction
- None
- Attack complexity
- High: exploitation depends on specific conditions
- Security boundary
- Changed: exploitation can affect a different security authority
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-20 ↗
CWE-20: Improper Input Validation. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:3.0/AV:A/AC:H/PR:H/UI:N/S:C/C:H/I:N/A:NCommon Vulnerability Scoring System 3.0: the compact vector below is decoded into plain language.
AVAdjacentAttack vector: The attacker must be on an adjacent or logically close network.ACHighAttack complexity: Successful exploitation depends on specific conditions outside the attacker's direct control.PRHighPrivileges required: The attacker needs elevated or administrative privileges.UINoneUser interaction: No action by another user is required.SChangedScope: The attack can affect a component governed by a different security authority.CHighConfidentiality impact: A successful attack can cause a major loss.INoneIntegrity impact: No direct loss is represented by this metric.ANoneAvailability impact: No direct loss is represented by this metric.- Post-exploitation / living off the land
- No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
03
Patch and workaround
Operational remediation based on structured source evidence.
- Status
?
Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change. - Patch available
- Affected
- Windows 7: x64-based Systems Service Pack 1
- Windows Server 2012 R2: (Server Core installation)
- Windows RT 8.1: Windows RT 8.1
- Windows Server 2008: x64-based Systems Service Pack 2, x64-based Systems Service Pack 2 (Server Core installation)
- Windows Server 2012: (Server Core installation)
- Windows 8.1: x64-based systems
- Windows Server 2016: (Server Core installation)
- Windows Server 2008 R2: x64-based Systems Service Pack 1, x64-based Systems Service Pack 1 (Server Core installation)
- Windows 10: Version 1607 for x64-based Systems, Version 1703 for x64-based Systems, Version 1709 for x64-based Systems, Version 1803 for x64-based Systems, x64-based Systems
- Windows 10 Servers: version 1709 (Server Core Installation), version 1803 (Server Core Installation)
- Action
- Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
- Workaround
- No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
04
Evidence and provenance
Published 13 Sept 2018 · Last source change 5 Aug 2024, 06:54 UTC · CWE-20 · Improper Input Validation
CVE recordCVE.org · 5.1
CVSS sourceNIST NVD
EPSS source FIRST · tracked since 2026-09-01
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2018-20070
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceNIST NVD
NVD statusNVD modified after enrichment
Core structured fields are present and their contributing authorities are shown above.
Material change intelligence
View recent updates ↗What changed after publication
- ENISA EUVD mappingEUVD-2018-20070 was added to the official ENISA EUVD mapping for this CVE.ENISA EUVD ↗
- Before
- not recorded
- After
- {"euvdId":"EUVD-2018-20070"}
- Vendor guidanceAuthoritative vendor guidance changed: added patch: portal.msrc.microsoft.com/CVE-2018-8434; added remediation: portal.msrc.microsoft.com/CVE-2018-8434.portal.msrc.microsoft.com ↗
- Before
- no authoritative guidance recorded
- After
- patch: portal.msrc.microsoft.com/CVE-2018-8434 · remediation: portal.msrc.microsoft.com/CVE-2018-8434
- Affected versionsThe structured affected or fixed version information changed.CNA ↗
- Before
- x64-based Systems Service Pack 1; (Server Core installation); Windows RT 8.1; x64-based Systems Service Pack 2; x64-based Systems Service Pack 2 (Server Core installation); x64-based systems; x64-based Systems Service Pack 1 (Server Core installation) · Fixed: No fixed version is explicitly recorded in the structured CVE data.
- After
- x64-based Systems Service Pack 1; (Server Core installation); Windows RT 8.1; x64-based Systems Service Pack 2; x64-based Systems Service Pack 2 (Server Core installation); x64-based systems; x64-based Systems Service Pack 1 (Server Core installation) · Fixed: An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
- Remediation statusRemediation status changed from Awaiting fix to Patch available.portal.msrc.microsoft.com ↗
- Before
- Awaiting fix
- After
- Patch available
- SeveritySeverity changed from Unknown to Medium.NIST NVD ↗
- Before
- Unknown
- After
- Medium
- CVSS scoreCVSS score changed from not recorded to 5.4 (CVSS 3.0 · NIST NVD · CVSS:3.0/AV:A/AC:H/PR:H/UI:N/S:C/C:H/I:N/A:N).NIST NVD ↗
- Before
- not recorded
- After
- 5.4 (CVSS 3.0 · NIST NVD · CVSS:3.0/AV:A/AC:H/PR:H/UI:N/S:C/C:H/I:N/A:N)
- Catalogue recordCVE added to the BlackTree catalogue.CNA ↗
CVE published
Fixed release or patch reference recorded
Technical terms and abbreviations used in this report
- CVE
- Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
- CVSS
- Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
- EPSS
- Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
- CWE
- Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
- CNA
- CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
- CISA ADP
- Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
- NVD
- National Vulnerability Database: NIST's enrichment service for CVE records.
- CERT / CSIRT
- A computer security incident response team that publishes warnings or coordinates incident response.
- PoC
- Proof of concept: public material that demonstrates or helps reproduce exploitation.
- CSAF
- Common Security Advisory Framework: a machine-readable format for security advisories.
- LoTL
- Living off the land: abuse of legitimate tools or system functions during an attack.