Analysis of the Alexa Top 1M sites

Prior to the release of the Mozilla Observatory a year ago, I ran a scan of the Alexa Top 1M websites. Despite being available for years, the usage rates of … Read more

The end of SHA-1 on the Public Web

Our deprecation plan for the SHA-1 algorithm in the public Web, first announced in 2015, is drawing to a close. Today a team of researchers from CWI Amsterdam and Google … Read more

Setting a Baseline for Web Security Controls

Securing modern web applications effectively is a complex process. However there are many straightforward security controls such as HTTP security headers which are very effective at blocking web common attacks. … Read more

Communicating the Dangers of Non-Secure HTTP

HTTPS, the secure variant of the HTTP protocol, has long been a staple of the modern Web. It creates secure connections by providing authentication and encryption between a browser and … Read more

Fixing an SVG Animation Vulnerability

At roughly 1:30pm Pacific time on November 30th, Mozilla released an update to Firefox containing a fix for a vulnerability reported as being actively used to deanonymize Tor Browser users. … Read more

Distrusting New WoSign and StartCom Certificates

Mozilla has discovered that a Certificate Authority (CA) called WoSign has had a number of technical and management failures. Most seriously, we discovered they were backdating SSL certificates in order … Read more

Phasing Out SHA-1 on the Public Web

An algorithm we’ve depended on for most of the life of the Internet — SHA-1 — is aging, due to both mathematical and technological advances. Digital signatures incorporating the SHA-1 … Read more

Update on add-on pinning vulnerability

Earlier this week, security researchers published reports that Firefox and Tor Browser were vulnerable to “man-in-the-middle” (MITM) attacks under special circumstances. Firefox automatically updates installed add-ons over an HTTPS connection. … Read more