The unauthenticated ``/get_image`` and ``/get_favicon`` endpoints accept
the admin-set env vars ``UI_LOGO_PATH`` and ``LITELLM_FAVICON_URL`` and
return whatever bytes they resolve to, with a hard-coded ``image/jpeg``
or ``image/x-icon`` content-type. Two attack shapes:
* ``UI_LOGO_PATH=/etc/passwd`` (or any other readable file path) — any
unauthenticated caller exfiltrates the file via ``GET /get_image``.
The previous gate was ``os.path.exists(logo_path)`` which fires on
every readable file. Same shape for the favicon endpoint.
* ``UI_LOGO_PATH=http://169.254.169.254/iam`` (or any internal HTTP
service the admin pointed at) — the proxy fetches it server-side
and streams the response body to the unauthenticated caller. No
URL validation, no Content-Type validation; ``application/json``
AWS metadata gets tunneled out under the ``image/jpeg`` wrapper.
New helper module ``litellm/proxy/common_utils/static_asset_utils.py``:
* ``resolve_local_asset_path(candidate, allowed_roots)`` — returns the
resolved absolute path only if it lives within one of the allowed
asset roots. Uses ``realpath`` so symlinks pointing outside the roots
are caught.
* ``fetch_validated_image_bytes(url)`` — runs the URL through
``validate_url`` (rejecting private / cloud-metadata / loopback
targets) and only returns the response body if the upstream
Content-Type is in a small allowlist of image MIME types.
Both ``/get_image`` and ``/get_favicon`` are wired through the helpers.
The SSRF gate is enforced unconditionally — these endpoints are
unauthenticated, so the admin-facing ``litellm.user_url_validation``
toggle does not apply (an admin who opted out of URL validation for
LLM provider paths shouldn't also expose ``/get_image`` to SSRF).
Tests:
- ``TestResolveLocalAssetPath``: 10 cases covering legitimate paths,
``/etc/passwd``, ``/proc/self/environ``, symlink-out, ``..``
traversal, directories, missing files, and root list edge cases.
- ``TestFetchValidatedImageBytes``: 7 cases covering SSRF block, non-
image content-type rejection, valid image passthrough, non-200
response, fetch exception, empty URL, and parametrized coverage of
every allowed image MIME type.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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