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, obtain sensitive
information, conduct spoofing attacks, bypass CSP restrictions, or
execute arbitrary code. (CVE-2021-43536, CVE-2021-43537, CVE-2021-43538,
CVE-2021-43539, CVE-2021-43541, CVE-2021-43542, CVE-2021-43543,
CVE-2021-43545, CVE-2021-43546)
A security issue was discovered with the handling of WebExtension
permissions. If a user were tricked into installing a specially crafted
extension, an attacker could potentially exploit this to create and
install a service worker that wouldn’t be uninstalled with the extension.
(CVE-2021-43540)
ubuntu.com/security/CVE-2021-43536
ubuntu.com/security/CVE-2021-43537
ubuntu.com/security/CVE-2021-43538
ubuntu.com/security/CVE-2021-43539
ubuntu.com/security/CVE-2021-43540
ubuntu.com/security/CVE-2021-43541
ubuntu.com/security/CVE-2021-43542
ubuntu.com/security/CVE-2021-43543
ubuntu.com/security/CVE-2021-43545
ubuntu.com/security/CVE-2021-43546
ubuntu.com/security/notices/USN-5186-1