Mozilla this week released Firefox 66 with support for Windows Hello for Web Authentication on Windows 10, as well as with patches for 21 vulnerabilities.
The newly added support for Windows Hello should provide users with a passwordless experience on the web, but also with increased security, Mozilla says.
The browser has Web Authentication support for all desktop platforms since version 60, and Windows 10 becomes the first to include support for the new FIDO2 “passwordless” capabilities for Web Authentication.
“Firefox users on the Windows Insider Program’s fast ring can use any authentication mechanism supported by Windows for websites via Firefox. That includes face or fingerprint biometrics, and a wide range of external security keys via the CTAP2 protocol from FIDO2, as well as existing deployed CTAP1 FIDO U2F-style security keys,” Mozilla says.
The feature will become available for the remaining Firefox users on Windows 10 in an upcoming update this spring. On older versions of Windows, Web Authentication will still use Mozilla’s Rust-implemented CTAP1 protocol support for U2F-style USB security keys, but CTAP2/FIDO2 support is also planned.
The Windows Hello support is also planned for Firefox ESR 60.0.7, which is expected to arrive mid-May.
Of the 21 vulnerabilities addressed with this release, 5 were Critical bugs, 7 High risk issues, 5 Moderate severity, and 4 Low risk.
The Critical flaws include a use-after-free when removing in-use DOM elements, type inference incorrect for constructors entered through on-stack replacement with IonMonkey, and IonMonkey just-in-time (JIT) compiler leaking an internal JS_OPTIMIZED_OUT magic value to the running script during a bailout. Mozilla also fixed critical memory safety bugs in Firefox 66 and Firefox ESR 60.6.
The High risk issues include improper bounds checks when Spectre mitigations are disabled, command line arguments not discarded during execution, type-confusion in IonMonkey JIT compiler, use-after-free with SMIL animation controller, cross-origin theft of images with createImageBitmap, and information disclosure via IPC channel messages.
On Android, Firefox can load a library from APITRACE_LIB, which is writable by all users and applications.
Mozilla also addressed a vulnerability where Windows programs that are not ‘URL Handlers’ are exposed to web content, a Chrome process information leak, code execution through ‘Copy as cURL’ in Firefox Developer Tools on macOS, and potential use of uninitialized memory in Prio. One other resolved issue resides in Upgrade-Insecure-Requests incorrectly being enforced for same-origin navigation.
Related: Chrome, Firefox Get Windows Defender Application Guard Extensions
Related: Firefox 65 Brings Improved Privacy Protections
Ionut Arghire is an international correspondent for SecurityWeek.
Tags: 
