Arch Linux Security Advisory ASA-202111-2 ========================================= Severity: High Date : 2021-11-05 CVE-ID : CVE-2021-38503 CVE-2021-38504 CVE-2021-38506 CVE-2021-38507 CVE-2021-38508 CVE-2021-38509 Package : firefox Type : multiple issues Remote : Yes Link : https://security.archlinux.org/AVG-2511 Summary ======= The package firefox before version 94.0-1 is vulnerable to multiple issues including arbitrary code execution, content spoofing, same- origin policy bypass and sandbox escape. Resolution ========== Upgrade to 94.0-1. # pacman -Syu "firefox>=94.0-1" The problems have been fixed upstream in version 94.0. Workaround ========== None. Description =========== - CVE-2021-38503 (sandbox escape) A security issue has been found in Firefox before version 94 and Thunderbird before version 91.3. The iframe sandbox rules were not correctly applied to XSLT stylesheets, allowing an iframe to bypass restrictions such as executing scripts or navigating the top-level frame. - CVE-2021-38504 (arbitrary code execution) A security issue has been found in Firefox before version 94 and Thunderbird before version 91.3. When interacting with an HTML input element's file picker dialog with "webkitdirectory" set, a use-after- free could have resulted, leading to memory corruption and a potentially exploitable crash. - CVE-2021-38506 (content spoofing) A security issue has been found in Firefox before version 94 and Thunderbird before version 91.3. Through a series of navigations, Firefox and Thunderbird could have entered fullscreen mode without notification or warning to the user. This could lead to spoofing attacks on the browser UI including phishing. - CVE-2021-38507 (same-origin policy bypass) A security issue has been found in Firefox before version 94 and Thunderbird before version 91.3. The Opportunistic Encryption feature of HTTP2 (RFC 8164) allows a connection to be transparently upgraded to TLS while retaining the visual properties of an HTTP connection, including being same-origin with unencrypted connections on port 80. However, if a second encrypted port on the same IP address (e.g. port 8443) did not opt-in to opportunistic encryption; a network attacker could forward a connection from the browser to port 443 to port 8443, causing the browser to treat the content of port 8443 as same-origin with HTTP. This was resolved by disabling the Opportunistic Encryption feature, which had low usage. - CVE-2021-38508 (content spoofing) A security issue has been found in Firefox before version 94 and Thunderbird before version 91.3. By displaying a form validity message in the correct location at the same time as a permission prompt (such as for geolocation), the validity message could have obscured the prompt, resulting in the user potentially being tricked into granting the permission. - CVE-2021-38509 (content spoofing) A security issue has been found in Firefox before version 94 and Thunderbird before version 91.3. Due to an unusual sequence of attacker-controlled events, a Javascript alert() dialog with arbitrary (although unstyled) contents could be displayed over top an uncontrolled webpage of the attacker's choosing. Impact ====== A remote attacker could execute arbitrary code, spoof content or bypass same-origin policy through crafted web content. References ========== https://www.mozilla.org/en-US/security/advisories/mfsa2021-48/ https://www.mozilla.org/security/advisories/mfsa2021-48/ https://www.mozilla.org/security/advisories/mfsa2021-50/ https://bugzilla.mozilla.org/show_bug.cgi?id=1729517 https://bugzilla.mozilla.org/show_bug.cgi?id=1730156 https://bugzilla.mozilla.org/show_bug.cgi?id=1730750 https://bugzilla.mozilla.org/show_bug.cgi?id=1730935 https://bugzilla.mozilla.org/show_bug.cgi?id=1366818 https://bugzilla.mozilla.org/show_bug.cgi?id=1718571 https://security.archlinux.org/CVE-2021-38503 https://security.archlinux.org/CVE-2021-38504 https://security.archlinux.org/CVE-2021-38506 https://security.archlinux.org/CVE-2021-38507 https://security.archlinux.org/CVE-2021-38508 https://security.archlinux.org/CVE-2021-38509