How to address WebView SSL Error Handler alerts in your apps.

This article is intended for developers using an unsafe implementation of the WebViewClient.onReceivedSslError handler in their apps. Specifically, the implementation ignores all SSL certificate validation errors, making the app vulnerable to man-in-the-middle attacks. An attacker could change the affected WebView's content, read transmitted data (such as login credentials), and execute code inside the app using JavaScript.  

What’s happening

Beginning November 25, 2016, Google Play started to block publishing of any new apps or updates that contain this vulnerability. Please refer to the notice on your Play ConsoleAfter the deadlines shown in your Play Console, any apps that contain unfixed security vulnerabilities may be removed from Google Play.

Action required​

  1. Sign in to your Play Console, and navigate to the Alerts section to see which apps are affected and the deadlines to resolve these issues.
  2. Update your affected apps and fix the vulnerability.
  3. Submit the updated versions of your affected apps.

Upon resubmission, your app will be reviewed again. This process can take several hours. If the app passes review and is published successfully, then no further action is required. If the app fails review, then the new app version will not be published and you will receive an email notification.

Additional details

  1. To correct the issue, please update your apps code to invoke SslErrorHandler.proceed() whenever the certificate presented by the server meets your expectations, and invoke SslErrorHandler.cancel() otherwise.
  2. If you are using a 3rd party library that’s responsible for this, please notify the 3rd party and work with them to address the issue.

For more information about the SSL error handler, please see our documentation in the Android Developers Help Center. For other technical questions, you can post to https://www.stackoverflow.com/questions and use the tags “android-security” and “SslErrorHandler.”

While these specific issues may not affect every app that uses WebView SSL, it’s best to stay up to date on all security patches. Apps with vulnerabilities that expose users to risk of compromise may be considered dangerous products in violation of the Content Policy and section 4.4 of the Developer Distribution Agreement.

We’re here to help

If you have technical questions about the vulnerability, you can post to Stack Overflow and use the tag “android-security.” For clarification on steps you need to take to resolve this issue, you can contact our developer support team.

Was this article helpful?
How can we improve it?