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ElectronApplication · Electronjs

CVE-2020-4077

CRITICAL · 9.9 CVSS v3.1 Published 2020-07-07
Fix available
A fix is available. Upgrade to 7.2.4 / 8.2.4 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable Zero-click

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
In Electron before versions 7.2.4, 8.2.4, and 9.0.0-beta21, there is a context isolation bypass. Code running in the main world context in the renderer can reach into the isolated Electron context and perform privileged actions. Apps using both `contextIsolation` and `contextBridge` are affected. This is fixed in versions 9.0.0-beta.21, 8.2.4 and 7.2.4.

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

Electron versions before 7.2.4, 8.2.4, and 9.0.0-beta21 contain a context isolation bypass vulnerability where code executing in the main world context of a renderer process can break out of the isolated context and perform privileged actions. This affects applications that use both contextIsolation and contextBridge APIs.

MitigationUpgrade Electron to version 7.2.4, 8.2.4, or 9.0.0-beta21 or later to patch the context isolation bypass.

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
ElectronApplication
Affected:>= 7.0.0, < 7.2.4>= 8.0.0, < 8.2.4= 9.0.0

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
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/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. Determine installed Electron version
    Run 'electron --version' in the application environment, or inspect the package.json dependencies to find the electron version specified, or check the electron binary version programmatically via process.versions.electron in a renderer
    Affected if The version is 7.0.0 through 7.2.3, 8.0.0 through 8.2.3, or exactly 9.0.0-beta21 (not including the patched versions 7.2.4+, 8.2.4+, or 9.0.0-beta22+)
  2. Locate webPreferences configuration
    Search project source code for BrowserWindow or webContents definitions that include webPreferences:{} - look for files like main.js, main.ts, or equivalent entry points where the Electron window is created
    Affected if A webPreferences object exists in the codebase (proceed to next check)
  3. Verify contextIsolation is enabled
    In the webPreferences object found, look for contextIsolation:true or confirm it defaults to true in the Electron version being used
    Affected if contextIsolation is set to true (or defaults to true in the affected version)
  4. Confirm contextBridge usage
    Search for 'contextBridge' and 'ipcRenderer' in preload scripts - look for files named preload.js, preload.ts, or similar that use contextBridge.exposeInMainWorld to expose APIs to the renderer
    Affected if The application uses contextBridge in a preload script to expose APIs to the renderer

You are affected if your Electron version falls within the vulnerable ranges (7.0.0-7.2.3, 8.0.0-8.2.3, or 9.0.0) AND your application uses both contextIsolation enabled and contextBridge APIs.

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
Upgrade available Upgrade to 7.2.4 / 8.2.4 or later
Fixed in 7.2.48.2.4
Interim mitigation

Upgrade Electron to version 7.2.4, 8.2.4, or 9.0.0-beta21 or later to patch the context isolation bypass.

Recommended fix High confidence

Electron 7.2.4, 8.2.4, or 9.0.0-beta.21 (or later stable releases)

  1. 1. Identify the current Electron version in your project by checking package.json or the electron dependency
  2. 2. If using Electron 7.x: upgrade to version 7.2.4 or later
  3. 3. If using Electron 8.x: upgrade to version 8.2.4 or later
  4. 4. If using Electron 9.x beta: upgrade to version 9.0.0-beta.21 or later, or consider the stable 9.x release that includes this fix
  5. 5. Run your application's test suite to verify functionality after the upgrade
  6. 6. Rebuild any native modules against the new Electron version using electron-rebuild if applicable
  7. 7. Test that contextIsolation and contextBridge are functioning correctly to confirm the security fix is effective
Caveat Electron major version upgrades may include breaking API changes; review the Electron changelog for your target version before upgrading

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

Fix this in Electron Scoped from the published advisory
  • Consultation1.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,040
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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-2020-4077 in production — separate from our analysis above.

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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