Affected: Mozilla Firefox ESR, Mozilla Thunderbird, Mozilla Firefox

A WebGL framebuffer was not initialized early enough, resulting in memory corruption and an out of bound write. This vulnerability affects Firefox ESR < 78.10, Thunderbird < 78.10, and Firefox < 88.

Affected: Ubuntu:16.04:LTS: firefox, Ubuntu:18.04:LTS: firefox, Ubuntu:20.04:LTS: firefox

Multiple security issues were discovered in Firefox. If a user were tricked into opening a specially crafted website, an attacker could potentially exploit these to cause a denial of service, spoof the browser UI, bypass security restrictions, trick the user into disclosing confidential information, or execute arbitrary code. (CVE-2021-23994, CVE-2021-23996, CVE-2021-23997, CVE-2021-23998, CVE-2021-23999, CVE-2021-24000, CVE-2021-24001, CVE-2021-29945, CVE-2021-29946, CVE-2021-29947)

A use-after-free was discovered when Responsive Design Mode was enabled. If a user were tricked into opening a specially crafted website with Responsive Design Mode enabled, an attacker could potentially exploit this to cause a denial of service, or execute arbitrary code. (CVE-2021-23995)

It was discovered that Firefox mishandled ftp URLs with encoded newline characters. If a user were tricked into clicking on a specially crafted link, an attacker could potentially exploit this to send arbitrary FTP commands. (CVE-2021-24002)