What are the potential risks and vulnerabilities when using the form auto-fill feature in browsers and third-party extensions?

The feature of auto-filling logins and passwords in web browsers significantly simplifies the user's daily interaction with the internet, but it carries hidden security threats. The main danger is that built-in browser mechanisms often store credentials in an insufficiently protected form, for example, with a minimal level of encryption or none at all if a strong master password or operating system PIN is not activated on the computer itself.

A special category of threats is represented by malicious scripts and phishing attacks using hidden form fields. Attackers can place invisible login and password fields on a compromised or fake website that are imperceptible to a regular user. The browser or third-party extension, recognizing the familiar page structure, automatically inserts the saved confidential data there, after which the script quietly transfers them to an attacker's third-party server without raising any suspicions from the account owner.

Third-party browser extensions claiming auto-fill features require special attention due to the risk of extended access rights. If an extension requests permission to read and modify data on all visited websites, this creates a potential vector for information theft. In the event of a compromise of such an extension developer's account or its sale to attackers, an update can turn into a tool for mass espionage on data entered by users.

To minimize such risks, it is recommended to follow basic digital hygiene rules. You should regularly check the list of saved passwords in your browser settings and delete outdated entries. Whenever possible, it is best to completely disable built-in browser auto-fill, delegating this task to a trusted specialized password manager that requires manual confirmation or biometric authentication for each form fill.