SB2021110228 - Multiple vulnerabilities in Mozilla Firefox and Firefox ESR
Published: November 2, 2021 Updated: December 20, 2021
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 13 secuirty vulnerabilities.
1) Security features bypass (CVE-ID: N/A)
The vulnerability allows a remote attacker to bypass implemented security restrictions.
The vulnerability exists in the way the post-redirect URL of the element is handled. When a user loaded a Web Extensions context menu, the Web Extension could access the post-redirect URL of the element clicked. If the Web Extension lacked the WebRequest permission for the hosts involved in the redirect, this would be a same-origin-violation leaking data the Web Extension should have access to.
2) Information disclosure (CVE-ID: N/A)
The vulnerability allows a remote attacker to gain access to potentially sensitive information.
The vulnerability exists due to incorrect implementation of the 'Copy Image Link' context menu action, which copies the final image URL after redirects. By embedding an image that triggered authentication flows - in conjunction with a Content Security Policy that stopped a redirection chain in the middle - the final image URL could be one that contained an authentication token used to takeover a user account. If a website tricked a user into copy and pasting the image link back to the page, the page would be able to steal the authentication tokens.
3) Input validation error (CVE-ID: N/A)
The vulnerability allows a remote attacker to perform spoofing attack.
The vulnerability exists due to insufficient validation of URL when parsing internationalized domain names. High bits of the characters in the URLs are sometimes stripped, resulting in inconsistencies that could lead to user confusion or attacks such as phishing.
4) Buffer overflow (CVE-ID: CVE-2021-43534)
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to a boundary error when processing HTML content. A remote attacker can create a specially crafted webpage, trick the victim into opening it, trigger memory corruption and execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
5) Security features bypass (CVE-ID: CVE-2021-38503)
The vulnerability allows a remote attacker to bypass implemented security restrictions.
The vulnerability exists due to the iframe sandbox rules were not correctly applied to XSLT stylesheets. A remote attacker can load use an iframe to bypass restrictions such as executing scripts or navigating the top-level frame.
6) Use-after-free (CVE-ID: CVE-2021-38504)
The vulnerability allows a remote attacker to compromise vulnerable system.
The vulnerability exists due to a use-after-free error when interacting with an HTML input element's file picker dialog with webkitdirectory set. A remote attacker can trick the victim to open a specially crafted website, trigger a use-after-free error and execute arbitrary code on the system.
Successful exploitation of the vulnerability may allow an attacker to compromise vulnerable system.
7) Information disclosure (CVE-ID: CVE-2021-38505)
The vulnerability allows a remote attacker to gain access to potentially sensitive information.
The vulnerability exists due to absence of support for a new feature in Windows 10 known as Cloud Clipboard that, if enabled, will record data copied to the clipboard to the
cloud, and make it available on other computers in certain scenarios. Applications that wish to prevent copied data from being recorded in Cloud History must use specific clipboard formats, which were not implemented in previous versions of Firefox and Firefox ESR.
8) Insufficient UI Warning of Dangerous Operations (CVE-ID: CVE-2021-38506)
The vulnerability allows a remote attacker to perform spoofing attacks.
The vulnerability exists due to Firefox could have entered fullscreen mode without notification or warning to the user. A remote attacker can perform spoofing attacks on the browser UI.
9) Security features bypass (CVE-ID: CVE-2021-38507)
The vulnerability allows a remote attacker to bypass implemented security restrictions.
The vulnerability exists in the Opportunistic Encryption feature of HTTP2, which 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 from port 443 to port 8443,
causing the browser to treat the content of port 8443 as same-origin
with HTTP. As a result, a remote attacker can bypass Same-Origin-Policy on services hosted on other ports.
10) Improper Restriction of Rendered UI Layers or Frames (CVE-ID: CVE-2021-38508)
The vulnerability allows a remote attacker to perform spoofing attack.
The vulnerability exists due to Firefox displays the 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.
11) Improper Restriction of Rendered UI Layers or Frames (CVE-ID: CVE-2021-38509)
The vulnerability allows a remote attacker to perform spoofing attack.
The vulnerability exists due to incorrect processing of an unusual sequence of attacker-controlled events. A remote attacker can display a Javascript alert() dialog with arbitrary (although unstyled) contents over top of arbitrary webpage of the attacker's choosing.
12) Insufficient UI Warning of Dangerous Operations (CVE-ID: CVE-2021-38510)
The vulnerability allows a remote attacker to silently download dangerous files on the system.
The vulnerability exists due to the executable file warning is not presented to the user when downloading .inetloc files. A remote attacker can silently download a potentially dangerous file to the user's system.
The vulnerability affects macOS operating system only.
13) Use-after-free (CVE-ID: CVE-2021-43535)
The vulnerability allows a remote attacker to compromise vulnerable system.
The vulnerability exists due to a use-after-free error when processing HTTP/2 session object. A remote attacker can trick the victim to open a specially crafted website, trigger a use-after-free error and execute arbitrary code on the system.
Successful exploitation of the vulnerability may allow an attacker to compromise vulnerable system.
Remediation
Install update from vendor's website.