When a malicious application successfully executes its own code inside your application’s WebView, it can operate within the trusted environment of
your app. This means it can misuse the permissions and access that your users have granted to your WebView. Depending on the case, an accacker could
execute JavaScript, redirect to phishing pages or access application’s private files.
What is the potential impact?
Theft of Sensitive Information
If the WebView shows private user details, such as personal information, financial data, or confidential documents, a malicious script can copy
this data and send it to an attacker. The script can also access session information, like cookies or authentication tokens.
Account Takeover
If an attacker obtains a user’s session token, they can often impersonate that user. The attacker can use the stolen token to access the user’s
account from their own device without needing the user’s password. Once inside, they could have full access to the account, allowing them to view
private data, change account settings, or lock the original user out.
Displaying Deceptive Content
An attacker’s script can change the content and appearance of the page shown in the WebView. For example, the script could display a fake login
screen that looks identical to your app’s real one. If a user enters their username and password into this fake form, the script sends the credentials
to the attacker. This technique is a form of phishing.
Performing Unauthorized Actions
Some applications set up a bridge that allows JavaScript in a WebView to communicate with the native part of the Android application. If this is
the case, a malicious script could potentially use this bridge to perform actions on behalf of the user. Depending on your app’s features, this could
include sending messages, modifying files, or accessing contacts.
