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: browsers
Browser Extensions: Powerful and Potentially Dangerous
Regular readers of my blogs know that I love browser extensions. Extensions can make using your browser more convenient, fun, and secure. Unfortunately, extensions can also break web apps in bizarre or amusing ways, dramatically slow your browser performance, leak your personal data, or compromise your device. The designers of the Chromium extension system createdContinue reading “Browser Extensions: Powerful and Potentially Dangerous”
Cloaking, Detonation, and Client-side Phishing Detection
Today, most browsers integrate security services that attempt to protect users from phishing attacks: for Microsoft’s Edge, the service is Defender SmartScreen, and for Chrome, Firefox, and many derivatives, it’s Google’s Safe Browsing. URL Reputation services do what you’d guess — they return a reputation based on the URL, and the browser will warn/block loadingContinue reading “Cloaking, Detonation, and Client-side Phishing Detection”
Troubleshooting Edge (or Chrome) Browser Crashes
In the modern browser world, there are two types of crashes: browser crashes and renderer crashes. In a browser crash, the entire browser window with all of its tabs simply vanishes, either on startup, or at some point afterward. The next time the browser starts, it should recognize that the last time it exited wasContinue reading “Troubleshooting Edge (or Chrome) Browser Crashes”
Protecting Auth Tokens
Authenticating to websites in browsers is complicated. There are numerous different approaches: Each of these authentication mechanisms has different user-experience effects and security properties. Sometimes, multiple systems are used at once, with, for example, a Web Forms login being bolstered by multifactor authentication. In most cases, however, Authentication mechanisms are only used to verify theContinue reading “Protecting Auth Tokens”
text/plain 