Microsoft

The Mozilla Maintenance Service does not guard against files being hardlinked to another file in the updates directory, allowing for the replacement of local files, including the Maintenance Service executable, which is run with privileged access. Additionally, there was a race condition during checks for junctions and symbolic links by the Maintenance Service, allowing for potential local file and directory manipulation to be undetected in some circumstances. This allows for potential privilege escalation by a user with unprivileged local access.
*Note: These attacks requires local system access and only affects Windows. Other operating systems are not affected.*. This vulnerability affects Firefox < 69 and Firefox ESR < 68.1.

Logging-related command line parameters are not properly sanitized when Firefox is launched by another program, such as when a user clicks on malicious links in a chat application. This can be used to write a log file to an arbitrary location such as the Windows ‘Startup’ folder.
*Note: this issue only affects Firefox on Windows operating systems.*. This vulnerability affects Firefox < 69 and Firefox ESR < 68.1.

The Firefox installer allows Firefox to be installed to a custom user writable location, leaving it unprotected from manipulation by unprivileged users or malware. If the Mozilla Maintenance Service is manipulated to update this unprotected location and the updated maintenance service in the unprotected location has been altered, the altered maintenance service can run with elevated privileges during the update process due to a lack of integrity checks. This allows for privilege escalation if the executable has been replaced locally.
*Note: This attack requires local system access and only affects Windows. Other operating systems are not affected.*. This vulnerability affects Firefox < 69, Firefox ESR < 60.9, and Firefox ESR < 68.1.