proof-of-concept: sanitise via bundled svg-hush, remove bespoke sanitizer#1
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davidtaylorhq wants to merge 1 commit into
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proof-of-concept: sanitise via bundled svg-hush, remove bespoke sanitizer#1davidtaylorhq wants to merge 1 commit into
svg-hush, remove bespoke sanitizer#1davidtaylorhq wants to merge 1 commit into
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Replace the in-house REXML/`SvgCss` SVG sanitizer with Cloudflare's memory-safe, fuzzed `svg-hush`, bundled as a prebuilt per-platform binary and run through the existing argv-only + Landlock path (no FFI). This deletes ~1.5k lines of bespoke parsing/CSS-allowlist code and the bug class that came with it: the prior `delete_attribute(local_name)` path let a namespace-prefixed `onload` survive on a real `<svg>` element, an executing same-origin XSS in `:standalone` output. `sanitize_svg!(path, max_pixels:)` now produces document-safe output only (the `id_namespace:` inline-into-DOM layer is removed). `SvgMetadata` still enforces the byte-size, encoding, and pixel pre-checks before the binary runs, so the `LimitError`/`InvalidImageError` hierarchy is unchanged. The operation no longer routes through the sandbox worker; `svg-hush` is its own sandboxed subprocess, and `Sandbox.capture_command!` now grants Landlock execute on the command's own directory so a gem-bundled binary outside the system bin dirs can run. Binaries are produced by `script/build-svg-hush.sh` from a pinned `svg-hush` version and vendored under `vendor/svg-hush/`; an unbundled platform raises rather than compiling at install.
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(AI-authored experiment. Unsuitable for merge)
Replace the in-house REXML/
SvgCssSVG sanitizer with Cloudflare's memory-safe, fuzzedsvg-hush, bundled as a prebuilt per-platform binary and run through the existing argv-only + Landlock path (no FFI). This deletes ~1.5k lines of bespoke parsing/CSS-allowlist code and the bug class that came with it: the priordelete_attribute(local_name)path let a namespace-prefixedonloadsurvive on a real<svg>element, an executing same-origin XSS in:standaloneoutput.sanitize_svg!(path, max_pixels:)now produces document-safe output only (theid_namespace:inline-into-DOM layer is removed).SvgMetadatastill enforces the byte-size, encoding, and pixel pre-checks before the binary runs, so theLimitError/InvalidImageErrorhierarchy is unchanged. The operation no longer routes through the sandbox worker;svg-hushis its own sandboxed subprocess, andSandbox.capture_command!now grants Landlock execute on the command's own directory so a gem-bundled binary outside the system bin dirs can run.Binaries are produced by
script/build-svg-hush.shfrom a pinnedsvg-hushversion and vendored undervendor/svg-hush/; an unbundled platform raises rather than compiling at install.