A universal cross-site scripting (UXSS) vulnerability, CVE-2020-6506 (https://crbug.com/1083819), has been identified in the Android WebView system component, which allows cross-origin iframes to execute arbitrary JavaScript in the top-level document. This vulnerability affects React Native apps which use a react-native-webview that allows navigation to arbitrary URLs, and when that app runs on systems with an Android WebView version prior to 83.0.4103.106.
Pending mitigation
Ensure users update their Android WebView system component via the Google Play Store to 83.0.4103.106 or higher to avoid this UXSS. 'react-native-webview' is working on a mitigation but it could take some time.
Update November 24, 2020: react-native-webview 11.0.0+ has introduced a new prop to mitigate this issue.
References
https://alesandroortiz.com/articles/uxss-android-webview-cve-2020-6506/
https://github.com/react-native-webview/react-native-webview/releases/tag/v11.0.0
alesandroortiz Analyst
A universal cross-site scripting (UXSS) vulnerability, CVE-2020-6506 (https://crbug.com/1083819), has been identified in the Android WebView system component, which allows cross-origin iframes to execute arbitrary JavaScript in the top-level document. This vulnerability affects React Native apps which use a
react-native-webviewthat allows navigation to arbitrary URLs, and when that app runs on systems with an Android WebView version prior to 83.0.4103.106.Pending mitigation
Ensure users update their Android WebView system component via the Google Play Store to 83.0.4103.106 or higher to avoid this UXSS. 'react-native-webview' is working on a mitigation but it could take some time.Update November 24, 2020:
react-native-webview11.0.0+ has introduced a new prop to mitigate this issue.References
https://alesandroortiz.com/articles/uxss-android-webview-cve-2020-6506/
https://github.com/react-native-webview/react-native-webview/releases/tag/v11.0.0