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Full vulnerability report · 2020
CVE-2020-1113High confidence

Windows Task Scheduler Security Feature Bypass Vulnerability

Microsoft · Windows 10 Version 1507

5.3MediumCVSS 3.1
Recommended action
Scheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Patch available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityMediumOperational priority:Medium, unchanged from published severity.unchanged

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • EPSS is 6.11% 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.
  • Monitor vendor guidance and exploitation sources for a material change.

Verification

  1. Confirm that the asset runs Microsoft Windows 10 Version 1507 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: As exposure requiresRemediation target: Within 365 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-2020-12000

No EUVD known-exploited evidence

A security feature bypass vulnerability exists in Microsoft Windows when the Task Scheduler service fails to properly verify client connections over RPC. An attacker who successfully exploited this vulnerability could run arbitrary code as an administrator. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. To exploit this vulnerability, a man-in-the-middle attacker would need to send a specially crafted request to a vulnerable system. The security update addresses the vulnerability by correcting how the Task Scheduler service validates connections.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
5.3 · CVSS 3.1
Advisory evidence
No linked advisory details stored yet
Recommended actionScheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Patch available
01

What, why and how

A security feature bypass vulnerability exists in Microsoft Windows when the Task Scheduler service fails to properly verify client connections over RPC. An attacker who successfully exploited this vulnerability could run arbitrary code as an administrator. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. To exploit this vulnerability, a man-in-the-middle attacker would need to send a specially crafted request to a vulnerable system. The security update addresses the vulnerability by correcting how the Task Scheduler service validates connections.

What

A security feature bypass vulnerability exists in Microsoft Windows when the Task Scheduler service fails to properly verify client connections over RPC. An attacker who successfully exploited this vulnerability could run arbitrary code as an administrator. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. To exploit this vulnerability, a man-in-the-middle attacker would need to send a specially crafted request to a vulnerable system. The security update addresses the vulnerability by correcting how the Task Scheduler service validates connections.

Why

The product does not validate, or incorrectly validates, a certificate.

How

An attacker operating through an adjacent network may attempt exploitation without authentication or user interaction. If successful, the issue may execute code or commands in the affected security context.

What

A security feature bypass vulnerability exists in Microsoft Windows when the Task Scheduler service fails to properly verify client connections over RPC. An attacker who successfully exploited this vulnerability could run arbitrary code as an administrator. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. To exploit this vulnerability, a man-in-the-middle attacker would need to send a specially crafted request to a vulnerable system. The security update addresses the vulnerability by correcting how the Task Scheduler service validates connections.

Why

The product does not validate, or incorrectly validates, a certificate.

How

An attacker operating through an adjacent network may attempt exploitation without authentication or user interaction. If successful, the issue may execute code or commands in the affected security context.

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.
No confirmed evidence

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
?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
an adjacent network → Improper Certificate Validation → execute code or commands in the affected security context
Attack surface
Adjacent
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
High: exploitation depends on specific conditions
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-295 ↗

CWE-295: Improper Certificate Validation. The product does not validate, or incorrectly validates, a certificate.

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

Common Vulnerability Scoring System 3.1: 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.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.IHighIntegrity impact: A successful attack can cause a major loss.ANoneAvailability impact: No direct loss is represented by this metric.
Post-exploitation / living off the land
After compromise, an attacker may use built-in shells, scripting engines, scheduled tasks and native network utilities for discovery, persistence or movement. This is a plausible LoTL path, not evidence that it has occurred for every attack.
UnauthenticatedRemote code executionCWE-295
A

Official authority intelligence

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

ENISA EUVD · EUVD-2020-12000Official EUVD mapping

A security feature bypass vulnerability exists in Microsoft Windows when the Task Scheduler service fails to properly verify client connections over RPC. An attacker who successfully exploited this vulnerability could run arbitrary code as an administrator. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. To exploit this vulnerability, a man-in-the-middle attacker would need to send a specially crafted request to a vulnerable system. The security update addresses the vulnerability by correcting how the Task Scheduler service validates connections.

Official EUVD record ↗
Cyber Security Agency of Singapore · English · CSA-SB-20200527Security Bulletin 27 May 2020

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 27 May 2020, published on 27 May 2020. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2020-AVI-287Multiples vulnérabilités dans Microsoft Windows

.cve.org/CVERecord?id=CVE-2020-1084 Référence CVE CVE-2020-1086 https://www.cve.org/CVERecord?id=CVE-2020-1086 Référence CVE CVE-2020-1087 https://www.cve.org/CVERecord?id=CVE-2020-1087 Référence CVE CVE-2020-1088 https://www.cve.org/CVERecord?id=CVE-2020-1088 Référence CVE CVE-2020-1090 https://www.cve.org/CVERecord?id=CVE-2020-1090 Référence CVE CVE-2020-1109 https://www.cve.org/CVERecord?id=CVE-2020-1109 Référence CVE CVE-2020-1110 https://www.cve.org/CVERecord?id=CVE-2020-1110 Référence CVE CVE-2020-1111 https://www.cve.org/CVERecord?id=CVE-2020-1111 Référence CVE CVE-2020-1112 https://www.cve.org/CVERecord?id=CVE-2020-1112 Référence CVE CVE-2020-1113 https://www.cve.org/CVERecord?id=CVE-2020-1113 Référence CVE CVE-2020-1114 https://www.cve.org/CVERecord?id=CVE-2020-1114 Référence CVE CVE-2020-1116 https://www.cve.org/CVERecord?id=CVE-2020-1116 Référence CVE CVE-2020-1117 https://www.cve.org/CVERecord?id=CVE-2020-1117 Référence CVE CVE-2020-1118 https://www.cve.org/CVERecord?id=CVE-2020-1118 Référence CVE CVE-2020-1121 https://www.cve.org/CVERecord?id=CVE-2020-1121 Référence CVE CVE-2020-1123 https://www.cve.org/CVERecord?id=CVE-2020-1123 Référence CVE CVE-2020-1124 https://www.cve.org/CVERecord?id=CVE-2020-1124 Référence CVE CVE-2020-1125 https://www.cve.org/CVERecord?id=CVE-2020-1125 Ré

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2020-005776複数の Microsoft Windows 製品におけるセキュリティ機能を回避される脆弱性

複数の Microsoft Windows 製品には、Microsoft Windows のタスクスケジューラサービスが RPC 経由のクライアント接続の適切な検証に失敗した場合、セキュリティ機能を回避される脆弱性が存在します。 ベンダは、本脆弱性を「Windows のタスク スケジューラのセキュリティ機能のバイパスの脆弱性」として公開しています。

Official advisory ↗
KISA KrCERT/CC · Korean · KNVD-5139MS 5월 보안 위협에 따른 정기 보안 업데이트 권고

- 보안 기능 우회(CVE-2020-1113)

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 21 May 2020 · Last source change 19 Aug 2026, 16:33 UTC · CWE-295 · Improper Certificate Validation

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2020-12000
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

What changed after publication

View recent updates ↗
  1. Vendor guidanceAuthoritative vendor guidance changed: added remediation: portal.msrc.microsoft.com/CVE-2020-1113; removed patch: msrc.microsoft.com/CVE-2020-1113; removed remediation: msrc.microsoft.com/CVE-2020-1113.
    Before
    patch: msrc.microsoft.com/CVE-2020-1113 · patch: portal.msrc.microsoft.com/CVE-2020-1113 · remediation: msrc.microsoft.com/CVE-2020-1113
    After
    patch: portal.msrc.microsoft.com/CVE-2020-1113 · remediation: portal.msrc.microsoft.com/CVE-2020-1113
    portal.msrc.microsoft.com ↗
  2. Vendor guidanceAuthoritative vendor guidance changed: added patch: msrc.microsoft.com/CVE-2020-1113; added remediation: msrc.microsoft.com/CVE-2020-1113; removed remediation: portal.msrc.microsoft.com/CVE-2020-1113.
    Before
    patch: portal.msrc.microsoft.com/CVE-2020-1113 · remediation: portal.msrc.microsoft.com/CVE-2020-1113
    After
    patch: msrc.microsoft.com/CVE-2020-1113 · patch: portal.msrc.microsoft.com/CVE-2020-1113 · remediation: msrc.microsoft.com/CVE-2020-1113
    msrc.microsoft.com ↗
  3. Affected versionsThe structured affected or fixed version information changed.
    Before
    10 Version 1803 for 32-bit Systems; 10 Version 1803 for x64-based Systems; 10 Version 1803 for ARM64-based Systems; 10 Version 1809 for 32-bit Systems; 10 Version 1809 for x64-based Systems; 10 Version 1809 for ARM64-based Systems; 10 Version 1709 for 32-bit Systems; 10 Version 1709 for x64-based Systems · 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
    10.0.10240.0 < publication; 10.0.14393.0 < publication; 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 ↗
  4. SeveritySeverity changed from High to Medium.
    Before
    High
    After
    Medium
    CNA ↗
  5. CVSS scoreCVSS score changed from 7.5 (CVSS 3.1 · NIST NVD · CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H) to 5.3 (CVSS 3.1 · CNA · CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N/E:P/RL:O/RC:C).
    Before
    7.5 (CVSS 3.1 · NIST NVD · CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H)
    After
    5.3 (CVSS 3.1 · CNA · CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N/E:P/RL:O/RC:C)
    CNA ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release or patch reference recorded
ENISA EUVD · EUVD-2020-12000↗Patch or update reference↗CVE authority or vendor 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-2020-1113 · cve.blacktree.nl