I received the following phishing lure by SMS a few days back: The syntax of URLs is complicated, and even tech-savvy users often misinterpret them. In the case of the URL above, the actual site’s hostname is brefjobgfodsebsidbg.com, and the misleading http://www.att.net:911 text is just a phony username:password pair making up the UserInfo component ofContinue reading “Attack Techniques: Spoofing via UserInfo”
Tag Archives: authentication
Attack Techniques: Phishing via Local Files
One attack technique I’ve seen in use recently involves enticing the victim to enter their password into a locally-downloaded HTML file. The attack begins by the victim receiving an email lure with a HTML file attachment (for me, often with the .shtml file extension): When the user opens the file, a HTML-based credential prompt isContinue reading “Attack Techniques: Phishing via Local Files”
The “Magical” Back Button
From the mailbag: Eric, when I am on bing.com in Edge or Chrome and I type https://portal.microsoft.com in the address bar, I go through some authentication redirections and end up on the Office website. If I then click the browser’s Back button, I go back to bing.com. But if I try the same thing inContinue reading “The “Magical” Back Button”
Web Proxy Authentication
Last year, I wrote about how the new Microsoft Edge’s adoption of the Chromium stack changed proxy determination away from the Windows Service (WinHTTP Proxy Service) to similar but not identical code in Chromium. This change mostly goes unnoticed, but it can have performance and functionality implications. In today’s post, I want to explore anotherContinue reading “Web Proxy Authentication”
Sandboxing vs. Elevated Browsing (As Administrator)
The Web Browser is the most security-critical application on most users’ systems– it accepts untrusted input from servers anywhere in the world, parses that input using dozens to hundreds of parsers, and renders the result locally as fast as it can. For performance reasons, almost all code in almost all browsers is written in memory-unsafeContinue reading “Sandboxing vs. Elevated Browsing (As Administrator)”
Seamless Single Sign-On
There are many different authentication primitives built into browsers. The most common include Web Forms authentication, HTTP authentication, client certificate authentication, and the new WebAuthN standard. Numerous different authentication frameworks build atop these, and many enterprise websites support more than one scheme. Each of the underlying authentication primitives has different characteristics: client certificate authentication isContinue reading “Seamless Single Sign-On”
Revealing Passwords
The Microsoft Edge browser, Edge Legacy, and Internet Explorer all offer a convenient mechanism for users to unmask their typing as they edit a password field: Clicking the little eye icon disables the masking dots so that users can see the characters they’re typing: This feature can be very useful for those of us whoContinue reading “Revealing Passwords”
Client Certificate Authentication
While most HTTPS sites only authenticate the server (using a certificate sent by the website), HTTPS also supports a mutual authentication mode, whereby the client supplies a certificate that authenticates the visiting user’s identity. Such a certificate might be stored on a SmartCard, or used as a part of an OS identity feature like WindowsContinue reading “Client Certificate Authentication”
Browser Password Managers: Threat Models
All major browsers have a built-in password manager. So we should use them, right? I Do I use my browser’s password manager because it’s convenient: with sync, I get all of my passwords on all of my devices. This convenience means that I can use a different password for every website, improving my security. ThisContinue reading “Browser Password Managers: Threat Models”
Challenges with Federated Identity in modern browsers
Many websites offer a “Log in” capability where they don’t manage the user’s account; instead, they offer visitors the ability to “Login with <identity provider>.” When the user clicks the Login button on the original relying party (RP) website, they are navigated to a login page at the identity provider (IP) (e.g. login.microsoft.com) and then redirectedContinue reading “Challenges with Federated Identity in modern browsers”
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