fix(media): route storage upload plans through the SSRF-safe fetch guard - #517
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The 0.0.18 fix for GHSA-rmm7 guarded the media storage READ path and left its write sibling on a raw fetch. A plugin holding only media.storage.adapter supplies the upload plan's step URLs, and the executor fetched them directly, so the grant conveyed network.outbound reach it never asked for: arbitrary PUT/POST at loopback, private, link-local, or cloud-metadata addresses, carrying plugin-chosen headers and the media bytes. executeStep now calls guardedFetch, exactly as mediaStorageReader does: internal addresses refused before a connection opens, connection pinned to the validated IP, every redirect hop re-checked. No host allowlist on either side, since an object-store endpoint is an arbitrary operator-chosen public host. Also corrects the mediaStorageRegistry doc comment, which asserted a networkAllowedHosts gate the code never implemented. The new architecture gate fails on any bare fetch( under server/handlers/cms/. Fixing one call site is what let this reopen, so the rule is file-scoped rather than call-site-scoped.
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The bug
A plugin holding only
media.storage.adaptersupplies the step URLs in a media upload plan, and the executor fetched them with a rawfetch(). The grant therefore carriednetwork.outboundreach it never asked for: arbitrary PUT/POST at loopback, private, link-local, or cloud-metadata addresses, with plugin-chosen headers and the media bytes as the body.This is the write-side sibling of GHSA-rmm7. That fix guarded the read path in 0.0.18 and left the write path untouched, one call site away.
The fix
executeStepnow callsguardedFetch, the same guardmediaStorageReaderuses: internal addresses refused before a connection opens, connection pinned to the validated IP, every redirect hop re-checked. No host allowlist on either side, since an object-store endpoint is an arbitrary operator-chosen public host.The new architecture gate fails on any bare
fetch(underserver/handlers/cms/, not just this call site, because fixing one call site is what let the class reopen. Also corrects themediaStorageRegistrydoc comment that asserted anetworkAllowedHostsgate the code never implemented.Reported as GHSA-9pq7-m5wf-r7f6.
Verification
Reproduced against a live loopback listener, before and after: