GHSA-5crw-6j7v-xc72 matrix-media-repo: Unsafe media served inline on download endpoints

• Go github.com/turt2live/matrix-media-repo: < 1.3.0 → fixed in 1.3.0

Impact A malicious user can upload an SVG image containing JavaScript to their server. When matrix-media-repo is asked to serve that media via the `/_matrix/media/(r0|v3)/download` endpoint, it would be served with a `Content-Disposition` of `inline`. This can allow JavaScript to run in the browser if a client links to the `/download` endpoint directly. Server operators which do not share a domain between matrix-media-repo and other services are not affected, but are encouraged to upgrade regardless. Patches https://github.com/turt2live/matrix-media-repo/commit/77ec2354e8f46d5ef149d1dcaf25f51c04149137 and https://github.com/turt2live/matrix-media-repo/commit/bf8abdd7a5371118e280c65a8e0ec2b2e9bdaf59 fix the issue. Operators should upgrade to v1.3.0 as soon as possible. Workarounds The `Content-Disposition` header can be overridden by the reverse proxy in front of matrix-media-repo to always use `attachment`, defeating this issue at the cost of "worse" user experience when clicking download links. References https://developer.mozilla.org/en-US/docs/Web/SVG/Element/script