Actively exploited in the wild. This CVE is on the CISA Known Exploited Vulnerabilities list — treat remediation as urgent. Federal remediation due by 3 May 2022.
Internet ExplorerApplication · Microsoft

CVE-2020-1380

HIGH · 7.8 CVSS v3.1 Published 2020-08-17
Patch available
A vendor patch is available. No clean upgrade release — apply the published patch.
See remediation →
96/100
Remediation priority · Urgent
In the wild Public exploit Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A remote code execution vulnerability exists in the way that the scripting engine handles objects in memory in Internet Explorer. The vulnerability could corrupt memory in such a way that an attacker could execute arbitrary code in the context of the current user. An attacker who successfully exploited the vulnerability could gain the same user rights as the current user. If the current user is logged on with administrative user rights, an attacker who successfully exploited the vulnerability could take control of an affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. In a web-based attack scenario, an attacker could host a specially crafted website that is designed to exploit the vulnerability through Internet Explorer and then convince a user to view the website. An attacker could also embed an ActiveX control marked "safe for initialization" in an application or Microsoft Office document that hosts the IE rendering engine. The attacker could also take advantage of compromised websites and websites that accept or host user-provided content or advertisements. These websites could contain specially crafted content that could exploit the vulnerability. The security update addresses the vulnerability by modifying how the scripting engine handles objects in memory.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

CVE-2020-1380 is a memory corruption vulnerability in Internet Explorer's scripting engine that allows remote code execution through specially crafted web pages or ActiveX controls. The vulnerability exploits improper handling of objects in memory, enabling attackers to execute arbitrary code in the context of the current user. User interaction is required (visiting a malicious website or opening a malicious document).

MitigationApply the relevant Microsoft security update (KB4561600, June 2020) to address the scripting engine vulnerability. Additionally, disable ActiveX controls in IE and enterprise browsers, and consider deploying Enhanced Mitigation Experience Toolkit (EMET) as a defense-in-depth measure.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Internet ExplorerApplication
Affected:= 11

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Verify Internet Explorer 11 is installed
    Open Command Prompt and run: reg query "HKLM\SOFTWARE\Microsoft\Internet Explorer" /v Version
    Affected if The version returned shows IE 11.x without the June 2020 or later security update installed
  2. Check installed Internet Explorer version and patch level
    Open IE, go to Help > About Internet Explorer, or run: reg query "HKLM\SOFTWARE\Microsoft\Internet Explorer" /v svcVersion
    Affected if The version shows 11.0.9600.xxxx where xxxx is lower than the build that includes the CVE-2020-1380 patch (June 2020 cumulative update or later)
  3. Determine if ActiveX controls are enabled
    Open IE > Internet Options > Security > Custom Level, or check registry: reg query "HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\3" /v 1001
    Affected if ActiveX controls and script ActiveX controls marked safe for scripting are set to Enable or Prompt (not Disable)
  4. Check if IE rendering engine is enabled in hosted scenarios
    Check if applications can embed IE rendering engine (MSHTML): review application document handling or check registry keys under HKLM\SOFTWARE\WOW6432Node\Microsoft\Internet Explorer\MAIN\FeatureControl
    Affected if Applications like Microsoft Office can embed IE rendering engine and this feature remains enabled

User is affected if Internet Explorer 11 is present without the June 2020 or later cumulative security update AND ActiveX or the IE rendering engine hosting capability is enabled.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Patch available Apply the vendor patch
Interim mitigation

Apply the relevant Microsoft security update (KB4561600, June 2020) to address the scripting engine vulnerability. Additionally, disable ActiveX controls in IE and enterprise browsers, and consider deploying Enhanced Mitigation Experience Toolkit (EMET) as a defense-in-depth measure.

Recommended fix High confidence

June 2020 cumulative security update for Internet Explorer 11 (KB4561608)

  1. Open Windows Update on the affected system
  2. Check for and install the June 2020 cumulative security update for Internet Explorer 11
  3. Alternatively, ensure Windows security updates are current via Windows Update
  4. Restart the system if prompted after installing updates
  5. Verify the update was installed by checking Windows Update history

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Internet Explorer Exploited in the wild — priority engagement
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA2.0 h
20.0 hours of engineering $3,500
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2020-1380 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2020-1380 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data