fix(proxy): ban caller-supplied aws identity selectors in request bodies

litellm/proxy/auth/auth_utils.py

@@ -262,6 +262,14 @@ _BANNED_REQUEST_BODY_PARAMS: Final[tuple[str, ...]] = (
     "aws_sts_endpoint",
     "aws_web_identity_token",
     "aws_role_name",
+    # Remaining AWS identity selectors. ``get_credentials`` prefers a named
+    # profile over the deployment's static keys, so a caller-supplied
+    # ``aws_profile_name`` signs Bedrock and S3 requests as any profile
+    # present on the proxy host; the two AssumeRole knobs are banned with it
+    # so the whole identity-selection family lives behind the same opt-in.
+    "aws_profile_name",
+    "aws_session_name",
+    "aws_external_id",
     "vertex_credentials",
     # Azure managed-identity / federated-auth token. The Azure provider
     # transformer reads ``azure_ad_token`` (top-level or via

tests/test_litellm/proxy/auth/test_auth_utils.py

@@ -3131,3 +3131,72 @@ class TestHasUserSetupSso:
 
         monkeypatch.setenv("SAML_IDP_METADATA_XML", "<EntityDescriptor/>")
         assert _has_user_setup_sso() is True
+
+
+class TestIsRequestBodySafeBlocksAwsIdentitySelectors:
+    """A caller must not be able to redirect Bedrock signing to another identity
+    reachable from the proxy host. ``get_credentials`` prefers a named profile
+    and the AssumeRole knobs over the deployment's static keys, and the file /
+    batch endpoints fold the request body and the deployment credentials into a
+    single params dict, so these have to be rejected at the boundary (#36155).
+    """
+
+    @pytest.mark.parametrize(
+        "selector",
+        ["aws_profile_name", "aws_session_name", "aws_external_id"],
+    )
+    def test_aws_identity_selector_in_batch_body_is_rejected(self, selector):
+        with pytest.raises(ValueError, match=selector):
+            is_request_body_safe(
+                request_body={
+                    "input_file_id": "file-abc123",
+                    "endpoint": "/v1/chat/completions",
+                    "completion_window": "24h",
+                    "model": "bedrock-batch-model",
+                    selector: "attacker-chosen",
+                },
+                general_settings={},
+                llm_router=None,
+                model="bedrock-batch-model",
+            )
+
+    @pytest.mark.parametrize(
+        "selector",
+        ["aws_profile_name", "aws_session_name", "aws_external_id"],
+    )
+    def test_aws_identity_selector_under_extra_body_is_rejected(self, selector):
+        with pytest.raises(ValueError, match=selector):
+            is_request_body_safe(
+                request_body={
+                    "model": "bedrock-batch-model",
+                    "extra_body": {selector: "attacker-chosen"},
+                },
+                general_settings={},
+                llm_router=None,
+                model="bedrock-batch-model",
+            )
+
+    def test_aws_identity_selector_allowed_under_proxy_wide_opt_in(self):
+        assert (
+            is_request_body_safe(
+                request_body={
+                    "model": "bedrock-batch-model",
+                    "aws_profile_name": "admin-approved-profile",
+                },
+                general_settings={"allow_client_side_credentials": True},
+                llm_router=None,
+                model="bedrock-batch-model",
+            )
+            is True
+        )
+
+    def test_upload_body_without_identity_selectors_is_accepted(self):
+        assert (
+            is_request_body_safe(
+                request_body={"purpose": "batch", "model": "bedrock-batch-model"},
+                general_settings={},
+                llm_router=None,
+                model="bedrock-batch-model",
+            )
+            is True
+        )

tests/test_litellm/proxy/auth/test_banned_params_extra_body.py

@@ -23,6 +23,7 @@ from litellm.proxy.auth.auth_utils import is_request_body_safe  # noqa: E402
         "aws_web_identity_token",
         "aws_sts_endpoint",
         "aws_role_name",
+        "aws_profile_name",
         "api_base",
         "base_url",
         "vertex_credentials",