CVE-2020-4076 in Electron
Summary
by MITRE
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 contextIsolation are affected. This is fixed in versions 9.0.0-beta.21, 8.2.4 and 7.2.4.
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Analysis
by VulDB Data Team • 10/28/2020
Electron applications are vulnerable to a context isolation bypass in versions prior to 7.2.4, 8.2.4, and 9.0.0-beta21 due to a flaw that allows code executing in the main world context of the renderer process to access and manipulate the isolated Electron context. This vulnerability represents a critical breakdown in the security model designed to protect applications from malicious code execution and privilege escalation attacks. The flaw specifically affects applications that implement context isolation as a security measure, which is a fundamental defense mechanism in Electron applications. According to CWE-284, this vulnerability directly relates to improper access control, where unauthorized access to privileged execution contexts is permitted. The security implications are severe as attackers can leverage this bypass to execute privileged operations that should be restricted to the isolated Electron context. This type of vulnerability falls under the ATT&CK technique T1059.001 for command and scripting interpreter, where attackers can execute malicious code with elevated privileges. The bypass occurs because the renderer process can access Electron APIs and privileged functions through the main world context, effectively undermining the security boundary that should separate user-controlled code from Electron's privileged execution environment. This flaw enables attackers to perform actions such as file system operations, network requests, and access to sensitive Electron APIs that should remain inaccessible to renderer processes. The vulnerability specifically impacts applications using contextIsolation, which is a recommended security practice that separates the renderer process from the Node.js environment to prevent code injection attacks. The fix implemented in versions 9.0.0-beta.21, 8.2.4, and 7.2.4 addresses this by properly enforcing the isolation boundaries between the main world context and the Electron isolated context. Organizations using Electron applications should immediately update to these patched versions to prevent exploitation of this vulnerability. The security implications extend beyond simple privilege escalation as this bypass can enable more sophisticated attacks including data exfiltration, system compromise, and persistence mechanisms. This vulnerability demonstrates the critical importance of proper context isolation implementation and the potential consequences when security boundaries are improperly enforced in modern web application frameworks. The flaw represents a significant risk to Electron-based applications that rely on context isolation as a primary security control, particularly affecting applications that handle sensitive data or operate in untrusted environments.