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Electron context isolation bypass via nested unserializable return value

Moderate severity GitHub Reviewed Published Sep 6, 2023 in electron/electron • Updated Nov 6, 2023

Package

npm electron (npm)

Affected versions

< 22.3.6
>= 23.0.0-alpha.1, < 23.2.3
>= 24.0.0-alpha.1, < 24.0.1
>= 25.0.0-alpha.1, < 25.0.0-alpha.2

Patched versions

22.3.6
23.2.3
24.0.1
25.0.0-alpha.2

Description

Impact

Apps using contextIsolation and contextBridge are affected.

This is a context isolation bypass, meaning that code running in the main world context in the renderer can reach into the isolated Electron context and perform privileged actions.

Workarounds

This issue is exploitable under either of two conditions:

  • If an API exposed to the main world via contextBridge can return an object or array that contains a JS object which cannot be serialized, for instance, a canvas rendering context. This would normally result in an exception being thrown Error: object could not be cloned.
  • If an API exposed to the main world via contextBridge has a return value that throws a user-generated exception while being sent over the bridge, for instance a dynamic getter property on an object that throws an error when being computed.

The app side workaround is to ensure that such a case is not possible. Ensure all values returned from a function exposed over the context bridge are supported and that any objects returned from functions do not have dynamic getters that can throw exceptions.

Auditing your exposed API is likely to be quite difficult so we strongly recommend you update to a patched version of Electron.

Fixed Versions

  • 25.0.0-alpha.2
  • 24.0.1
  • 23.2.3
  • 22.3.6

For more information

If you have any questions or comments about this advisory, email us at [email protected]

References

@MarshallOfSound MarshallOfSound published to electron/electron Sep 6, 2023
Published to the GitHub Advisory Database Sep 6, 2023
Reviewed Sep 6, 2023
Published by the National Vulnerability Database Sep 6, 2023
Last updated Nov 6, 2023

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
High
Privileges required
Low
User interaction
None
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
Low

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:L

EPSS score

0.089%
(39th percentile)

Weaknesses

CVE ID

CVE-2023-29198

GHSA ID

GHSA-p7v2-p9m8-qqg7

Source code

Credits

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