The container exec-read piped the whole file through base64 with no size
guard — the 50MB cap was only enforced host-side AFTER the full payload
had already streamed into host memory. A prompt-injected read of a huge
container file (or /dev/zero) could balloon the gateway process.
head -c (cap+1) bounds the read inside the sandbox; the +1 byte lets the
host distinguish at-cap from over-cap and reject with SourceTooLarge.
Input redirect replaces 'base64 --' (no argv exposure at all for
leading-dash paths). Docker integration tests re-verified live.
- _normalize_to_supported_image: ensure cache/vision exists before writing
the converted PNG (fresh HERMES_HOME had no dir -> FileNotFoundError).
- resolver: SVG passes through as image/svg+xml instead of erroring; the
call sites rasterize to PNG via the salvaged normalize step (cairosvg /
svglib / rsvg-convert / inkscape, best-effort with actionable error).
- normalization offloaded via asyncio.to_thread at both call sites.
- tests: resolver pass-through + rasterization + no-converter error paths.
- AUTHOR_MAP: jonathan@mintrx.com -> JAlmanzarMint (PR #52688 salvage).
vision_analyze embedded SVG (and BMP/TIFF) tool-results into conversation
history with media_type image/svg+xml. Anthropic only accepts jpeg/png/
gif/webp, so the request fails with a non-retryable 400. Because the image
is baked into immutable history and re-sent every turn, the session is
permanently wedged on resume — retries re-send the same bad bytes.
Add _normalize_to_supported_image(): SVG is rasterized to PNG (best-effort
via cairosvg/svglib/rsvg-convert/inkscape), other non-supported raster
formats are re-encoded to PNG via Pillow, and if conversion is impossible
the tool returns an actionable error instead of a session-wedging payload.
Wired into both the native-vision fast path and the auxiliary-API path so
the whole bug class is covered, not just the one call site.
All 99 existing vision tests pass.
- resolve_image_source: bare cwd-relative filenames ('pic.png') resolve
again (main accepted them; the path-shape gate regressed them — review
by egilewski). Unknown explicit schemes (ftp://, s3://) still rejected.
- Local backend: nonexistent path now raises a clean 'image file not
found' instead of a misleading sandbox-fallback message.
- W4: remove the now-dead path-based _detect_image_mime_type (suffix-trust
SVG acceptance) so future callers can't reintroduce it.
- W3: SVG sources rejected with a dedicated actionable message + test.
- Polish: host read_bytes / temp-file write_bytes offloaded via
asyncio.to_thread (matches the container exec-read); unused
ResolveContext.cfg/extra_roots fields dropped; duplicate policy check
documented as intentional pre-flight short-circuit.
Salvage of #35362, evolved to also close the vision sandbox-escape
(GHSA-gpxw-6wxv-w3qq). The two were the same root cause — vision read image
bytes host-side while every other tool reads through the terminal backend —
so one resolver fixes both the delivery gaps and the escape.
Delivery (from #35362, re-authored against current main since the branch was
4140 commits stale and vision_tools.py had been rewritten on both sides):
- tools/image_source.py: one resolver for data:/http(s)/file/local/container
image sources, returning raw bytes through a single magic-byte-sniff +
50MB-ingest chokepoint. Fixes 'no image attached' / 'Invalid image source'
for every source type (#7571, #25118, #29643, #22328, #32709, #9077).
- tools/credential_files.py: from_agent_visible_cache_path, the container->host
cache reverse-map (inverse of the existing forward twin).
- tools/vision_tools.py: both vision sites route through the resolver with
task_id threaded from the handler; resolved bytes are materialized to a temp
file so main's evolved encode/resize/embed-cap pipeline is reused verbatim
(kept over the PR's older bytes-core resize to avoid touching browser_tool /
conversation_compression callers).
Security (fills #35362's deliberately-stubbed _within_allowed_roots seam):
- Under a non-local terminal backend the file tools are confined to the sandbox
(SECURITY.md 2.2), but vision read host-side — a prompt-injected
vision_analyze('/etc/passwd') exfiltrated host secrets, and read_file even
redirects the model to vision_analyze for image paths. The resolver now
enforces the same boundary: local backend reads any host path (chosen
posture); non-local backend host-reads ONLY the media caches under
HERMES_HOME (where the gateway/download media lives) and routes every other
path to an in-sandbox base64 exec-read — which reads the CONTAINER's file,
the same one 'cat' would, never the host's. Paths are resolve()-d so a
symlink can't escape a cache; fail-closed when no sandbox env exists.
This closes the escape AND delivers container-only images (#32709) with the
same mechanism.
Tests: unified resolver + confinement model (tests/tools/test_image_source.py,
incl. proof a non-cache host path under Docker yields container bytes not the
host secret); existing vision tests updated to the resolver boundary; Docker
integration test verified green against a real daemon (exec-read of a tmpfs
/workspace file, a root-owned mode-600 file, and the host-secret invariant).
Fixes GHSA-gpxw-6wxv-w3qq.
Co-authored-by: banditburai <promptsiren@gmail.com>
