MFSA2022-13 Firefox: Security Vulnerabilities fixed in Firefox 99 (CVE-2022-28284)

SVG's <code><use></code> element could have been used to load unexpected content that could have executed script in certain circumstances. While the specification seems to allow this, other browsers do not, and web developers relied on this property for script security so gecko's implementation was aligned with theirs. This vulnerability affects Firefox < 99.