A fairly common security bug report is of the form: “I can put JavaScript inside a PDF file and it runs!” For example, open this PDF file with Chrome, and you can see the alert(1) message displayed: Support for JavaScript within PDFs is by-design and expected by the developers of PDF rendering software, including commonContinue reading “Browser Security Bugs that Aren’t: JavaScript in PDF”
Tag Archives: SecurityBugsThatArent
How do Random Credentials Mysteriously Appear?
One commonly-reported issue to browsers’ security teams sounds like: “Some random person’s passwords started appearing in my browser password manager?!? This must be a security bug of some sort!” This issue has been reported dozens of times, and it’s a reflection of a perhaps-surprising behavior of browser login and sync. So, what’s happening? Background EvenContinue reading “How do Random Credentials Mysteriously Appear?”
Attack Techniques: Spoofing via UserInfo
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”
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”
Browser Password Managers: Threat Models
All major browsers have a built-in password manager. So we should use them, right? I Do Should You? The easy answer is “Yes, use your browser’s password manager!“ The more nuanced answer begins: “Tell me about your threat model?” As when evaluating almost any security feature, my threat model might not match your threat model,Continue reading “Browser Password Managers: Threat Models”
Stealing your own password is not a vulnerability
By far, the most commonly-reported “vulnerability” reported to the Chrome Vulnerability Rewards program boils down to “I can steal my own password.” Despite having its very own FAQ entry, this gets reported to the VRP at varying levels of breathlessness, sometimes multiple times per day. You can see this “attack” in action: Yes, it’s true,Continue reading “Stealing your own password is not a vulnerability”
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