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Full vulnerability report · 2019
CVE-2019-1064High confidence

Microsoft Windows AppX Deployment Service (AppXSVC) Privilege Escalation Vulnerability

Microsoft · Windows

7.8HighCVSS 3.1
Recommended action
Patch now

CISA confirms exploitation in the wild and lists 2022-04-05 as the remediation due date.

Patch available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityHighOperational priority:Critical, raised one band.upgradedsince 15 Mar 2022

Evidence used

  • CISA confirms exploitation in the wild.
  • Exploitation requires an existing local or physical foothold with privileges.
  • EPSS is 6.89% for the current model date.

Compensating controls

  • Validate the affected product branch and deploy the verified fixed release.
  • Restrict local access and enforce least privilege on affected hosts.
  • Increase monitoring for the attack path and post-exploitation behaviour described in the report.

Verification

  1. Confirm that the asset runs Microsoft Windows and falls inside the recorded affected range.
  2. Verify the installed build against the product-specific fixed version after deployment.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: Within 3 daysRemediation target: Within 90 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2019-9646

CISA KEV mirrored by ENISA

An elevation of privilege vulnerability exists when Windows AppX Deployment Service (AppXSVC) improperly handles hard links. An attacker who successfully exploited this vulnerability could run processes in an elevated context. An attacker could then install programs; view, change or delete data. To exploit this vulnerability, an attacker would first have to log on to the system. An attacker could then run a specially crafted application that could exploit the vulnerability and take control of an affected system. The security update addresses the vulnerability by correcting how Windows AppX Deployment Service handles hard links.

EUVD state
Present in the current official mapping
Known exploitation
Recorded by ENISA since 15 Mar 2022. Evidence sources: cisa_kev.
ENISA score
7.8 · CVSS 3.1
Advisory evidence
No linked advisory details stored yet
Recommended actionPatch now

CISA confirms exploitation in the wild and lists 2022-04-05 as the remediation due date.

Patch available
01

What, why and how

A privilege escalation vulnerability exists when Windows AppXSVC improperly handles hard links. An attacker who successfully exploited this vulnerability could run processes in an elevated context.

What

A privilege escalation vulnerability exists when Windows AppXSVC improperly handles hard links. An attacker who successfully exploited this vulnerability could run processes in an elevated context.

Why

The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.

How

An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may gain additional privileges.

What

A privilege escalation vulnerability exists when Windows AppXSVC improperly handles hard links. An attacker who successfully exploited this vulnerability could run processes in an elevated context.

Why

The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.

How

An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may gain additional privileges.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
Confirmed in the wild

CISA added this CVE to its Known Exploited Vulnerabilities catalogue on 2022-03-15. Known ransomware campaign use is recorded.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

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
local access → Improper Link Resolution Before File Access ('Link Following') → gain additional privileges
Attack surface
Local
Privileges required
Low: a basic authenticated account is required
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-59 ↗

CWE-59: Improper Link Resolution Before File Access ('Link Following'). The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVLocalAttack vector: The attacker needs local access to the vulnerable system.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
The issue can support a local privilege or sandbox boundary transition; normal system utilities may then be available in the gained context.
Privilege escalationCWE-59CISA KEV
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

ENISA EUVD · EUVD-2019-9646Known-exploited evidence recorded

An elevation of privilege vulnerability exists when Windows AppX Deployment Service (AppXSVC) improperly handles hard links. An attacker who successfully exploited this vulnerability could run processes in an elevated context. An attacker could then install programs; view, change or delete data. To exploit this vulnerability, an attacker would first have to log on to the system. An attacker could then run a specially crafted application that could exploit the vulnerability and take control of an affected system. The security update addresses the vulnerability by correcting how Windows AppX Deployment Service handles hard links.

Official EUVD record ↗
CERT-FR · French · CERTFR-2019-AVI-264Multiples vulnérabilités dans Microsoft Windows

.cve.org/CVERecord?id=CVE-2019-1043 Référence CVE CVE-2019-1044 https://www.cve.org/CVERecord?id=CVE-2019-1044 Référence CVE CVE-2019-1045 https://www.cve.org/CVERecord?id=CVE-2019-1045 Référence CVE CVE-2019-1046 https://www.cve.org/CVERecord?id=CVE-2019-1046 Référence CVE CVE-2019-1047 https://www.cve.org/CVERecord?id=CVE-2019-1047 Référence CVE CVE-2019-1048 https://www.cve.org/CVERecord?id=CVE-2019-1048 Référence CVE CVE-2019-1049 https://www.cve.org/CVERecord?id=CVE-2019-1049 Référence CVE CVE-2019-1050 https://www.cve.org/CVERecord?id=CVE-2019-1050 Référence CVE CVE-2019-1053 https://www.cve.org/CVERecord?id=CVE-2019-1053 Référence CVE CVE-2019-1064 https://www.cve.org/CVERecord?id=CVE-2019-1064 Référence CVE CVE-2019-1065 https://www.cve.org/CVERecord?id=CVE-2019-1065 Référence CVE CVE-2019-1069 https://www.cve.org/CVERecord?id=CVE-2019-1069 Gestion détaillée du document le 12 juin 2019 Version initiale Alertes Avis Bulletins d’actualités Mentions légales Conditions générales À propos Contact cyber.gouv.fr service-public.fr legifrance.gouv.fr info.gouv.fr france.fr info.gouv.fr/risques Premier Ministre / Secrétariat Général de la Défense et de la Sécurité Nationale / Agence nationale de la sécurité des systèmes d'information

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2019-005516複数の Microsoft Windows 製品における権限を昇格される脆弱性

複数の Microsoft Windows 製品には、Windows AppX Deployment Service (AppXSVC) がハードリンクを適切に処理しない場合、権限を昇格される脆弱性が存在します。 ベンダは、本脆弱性を「Windows の特権の昇格の脆弱性」として公開しています。

Official advisory ↗
KISA KrCERT/CC · Korean · KNVD-5016MS 6월 보안 위협에 따른 정기 보안 업데이트 권고

- 권한상승 취약점(CVE-2019-0943,CVE-2019-0959,CVE-2019-0973,CVE-2019-0983,CVE-2019-0984,CVE-2019-0986,CVE-2019-0998,CVE-2019-1007,CVE-2019-1014,CVE-2019-1017,CVE-2019-1018,CVE-2019-1021,CVE-2019-1022,CVE-2019-1026,CVE-2019-1027,CVE-2019-1028,CVE-2019-1041,CVE-2019-1053,CVE-2019-1064,CVE-2019-1065,CVE-2019-1069)

Official advisory ↗
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
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.
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 12 Jun 2019 · Last source change 21 Oct 2025, 23:45 UTC · CWE-59 · Improper Link Resolution Before File Access ('Link Following')

CVE recordCVE.org · 5.1
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-09-01
European sourceENISA EUVD · EUVD-2019-9646
Product sourceCISA KEV
Remediation sourceCVE/CNA references
CWE sourceCISA ADP
NVD statusNVD enriched

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗
  1. ENISA known-exploited stateENISA EUVD now records this CVE in its known-exploited dataset.
    Before
    not listed in ENISA EUVD known-exploited dataset
    After
    listed in ENISA EUVD known-exploited dataset (EUVD-2019-9646)
    ENISA EUVD ↗
  2. ENISA EUVD mappingEUVD-2019-9646 was added to the official ENISA EUVD mapping for this CVE.
    Before
    not recorded
    After
    {"euvdId":"EUVD-2019-9646"}
    ENISA EUVD ↗
  3. Affected versionsThe structured affected or fixed version information changed.
    Before
    10.0.0 < publication; 10.0.17763.0 < publication · 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.
    After
    Windows 10 Version 1703: 10.0.0 < publication; Windows 10 Version 1803: 10.0.0 < publication; Windows Server, version 1803 (Server Core Installation): 10.0.0 < publication; Windows 10 Version 1809: 10.0.17763.0 < publication, 10.0.0 < publication; Windows Server 2019: 10.0.17763.0 < publication; Windows Server 2019 (Server Core installation): 10.0.17763.0 < publication; Windows 10 Version 1709 for 32-bit Systems: 10.0.0 < publication; Windows 10 Version 1709: 10.0.0 < publication; Windows 10 Version 1903 for 32-bit Systems: 10.0.0 < publication; Windows 10 Version 1903 for x64-based Systems: 10.0.0 < publication; Windows 10 Version 1903 for ARM64-based Systems: 10.0.0 < publication; Windows Server, version 1903 (Server Core installation): 10.0.0 < publication; Windows 10 Version 1607: 10.0.14393.0 < publication; Windows Server 2016: 10.0.14393.0 < publication; Windows Server 2016 (Server Core installation): 10.0.14393.0 < publication · 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.
    CNA ↗
  4. Vendor guidanceAuthoritative vendor guidance changed: added patch: msrc.microsoft.com/CVE-2019-1064; added patch: portal.msrc.microsoft.com/CVE-2019-1064; removed vendor advisory: msrc.microsoft.com/CVE-2019-1064; 1 further additions.
    Before
    vendor advisory: msrc.microsoft.com/CVE-2019-1064
    After
    patch: msrc.microsoft.com/CVE-2019-1064 · patch: portal.msrc.microsoft.com/CVE-2019-1064 · remediation: msrc.microsoft.com/CVE-2019-1064
    secure@microsoft.com ↗
  5. Affected versionsThe structured affected or fixed version information changed.
    Before
    10.0.0 < publication; 10.0.17763.0 < publication · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    After
    10.0.0 < publication; 10.0.17763.0 < publication · 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.
    CNA ↗
  6. Remediation statusRemediation status changed from Awaiting fix to Patch available.
    Before
    Awaiting fix
    After
    Patch available
    secure@microsoft.com ↗
  7. Catalogue recordCVE added to the BlackTree catalogue.
    CNA ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Added to CISA KEV
Fixed release or patch reference recorded
ENISA EUVD · EUVD-2019-9646↗CISA KEV record↗CVE authority or vendor reference↗Patch or update reference↗Official CVE record (CNA and ADP data)↗NVD record↗
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.
Free version - for non-commercial use only.CVE-2019-1064 · cve.blacktree.nl