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.* External Reference: https://www.mozilla.org/en-US/security/advisories/mfsa2019-26/#CVE-2019-11736
Acknowledgments: Name: the Mozilla project Upstream: Seb Patane
Statement: This vulnerability only affected Firefox on the Windows operating system. Firefox on Red Hat Enterprise Linux is not affected.
This bug is now closed. Further updates for individual products will be reflected on the CVE page(s): https://access.redhat.com/security/cve/cve-2019-11736