Tom Jøran Sønstebyseter Rønning (@L1v1ng0ffTh3L4N) on X

2 min read Original article ↗

Post

Post

  • user avatar

    Microsoft Edge loads all your saved passwords into memory in cleartext — even when you’re not using them.

  • user avatar

    When you save passwords in Edge, the browser decrypts every credential at startup and keeps them resident in process memory. This happens even if you never visit a site that uses those credentials.

    user avatar

    At the same time, Edge requires you to re‑authenticate before showing those same passwords in the Password Manager UI — yet the browser process already has them all in plaintext.

    user avatar

    Edge is the only Chromium‑based browser I’ve tested that behaves this way. By contrast, Chrome uses a design that makes it far harder for attackers to extract saved passwords by simply reading process memory.

    user avatar

    It decrypts credentials only when needed, instead of keeping all passwords in memory at all times. App‑Bound Encryption (ABE) adds another layer by binding decryption to an authenticated Chrome process, preventing other processes from reusing Chrome’s encryption keys.

    user avatar

    Because of these controls, plaintext passwords appear only briefly during autofill or when the user views them, making broad memory scraping far less effective. The risk of keeping the passwords in cleartext in memory becomes evident in shared environments.

    user avatar

    If an attacker gains administrative access on a terminal server, they can access the memory of all logged‑on user processes. In the video the attacker has compromised a user account with administrative rights and is able to view stored credentials for two other logged on

    user avatar

    (or even disconnected) users with Edge running. I reported this to Microsoft, and the official response was that the behavior is "by design". They have been informed that I would be sharing this as a responsible disclosure so users and organizations can make informed decisions

    user avatar

    about how they manage credentials. Last wednesday (April 29th) I disclosed this on BigBiteOfTech by

    @PaloAltoNtwks

    Norway, and showed a simple, educational tool, that I will be releasing on GitHub to help people easily see that the passwords are stored in cleartext in memory.

  • user avatar

    The proof of concept for this issue is live - contact me if you have any issues. I am not very experienced in C#, nor in publishing on GitHub, so any feedback is appreciated. github.com/L1v1ng0ffTh3L4…

  • user avatar

    Ah, the only thing written by Microsoft in that browser?