The Mozilla Foundation has patched seven High risk vulnerabilities in Firefox 94, as well as added a security feature site isolation that guards against side-channel attacks.
An attacker could exploit these vulnerabilities to take control of impacted systems.
As part of Mozilla Foundation Security Advisory 2021-48, Firefox 94 addressed the following seven High severity vulnerabilities:
- CVE-2021-38503: iframe sandbox rules did not apply to XSLT stylesheets.
- CVE-2021-38504: Use-after-free in file picker dialog.
- CVE-2021-38505: Windows 10 Cloud Clipboard may have recorded sensitive user data.
- CVE-2021-38506: Firefox could be coaxed into going into fullscreen mode without notification or warning.
- CVE-2021-38507: Opportunistic Encryption in HTTP2 could be used to bypass the Same-Origin-Policy on services hosted on other ports.
- MOZ-2021-0003: Universal XSS in Firefox for Android via QR Code URLs (pending a CVE assignment).
- MOZ-2021-0007: Memory safety bugs fixed in Firefox 94 and Firefox ESR 91.3 (pending a CVE assignment).
The memory safety bug could allow an attacker to exploit and then run arbitrary code. To add, four other Moderate and two Low severity vulnerabilities were also patched.
Moreover, the latest release of Firefox 94 includes a number of new features and security improvements. For instance, Firefox now includes Site Isolation that protects Firefox users against side-channel attacks such as Spectre.
Finally, Mozilla also released security updates for Firefox ESR 91.3 and Thunderbird 91.3.