Patches to prevent XSS

engine/src/main/java/io/seldon/engine/filters/XSSFilter.java

@@ -0,0 +1,25 @@
+package io.seldon.engine.filters;
+
+import java.io.IOException;
+
+import org.springframework.web.filter.OncePerRequestFilter;
+import org.springframework.stereotype.Component;
+
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import javax.servlet.FilterChain;
+import javax.servlet.ServletException;
+
+@Component
+public class XSSFilter extends OncePerRequestFilter {
+    @Override
+    protected void doFilterInternal(
+        HttpServletRequest request,
+        HttpServletResponse response, 
+        FilterChain filterChain)  throws ServletException, IOException {
+      // Add nosniff option to avoid content sniffing by the browser
+      response.addHeader("X-Content-Type-Options", "nosniff");
+
+      filterChain.doFilter(request, response);
+    }
+}

engine/src/main/java/io/seldon/engine/pb/JsonFormat.java

@@ -549,7 +549,7 @@ private static final class PrinterImpl {
     private final CharSequence blankOrNewLine;
 
     private static class GsonHolder {
-      private static final Gson DEFAULT_GSON = new GsonBuilder().disableHtmlEscaping().create();
+      private static final Gson DEFAULT_GSON = new GsonBuilder().create();
     }
 
     PrinterImpl(

engine/src/test/java/io/seldon/engine/api/rest/TestRandomABTest.java

@@ -30,6 +30,7 @@
 import org.springframework.util.MultiValueMap;
 import org.springframework.web.context.WebApplicationContext;
 
+import io.seldon.engine.filters.XSSFilter;
 import io.seldon.engine.pb.JsonFormat;
 import io.seldon.engine.predictors.EnginePredictor;
 import io.seldon.engine.service.InternalPredictionService;
@@ -64,6 +65,7 @@ public class TestRandomABTest {
 	public void setup() throws Exception {
     	mvc = MockMvcBuilders
 				.webAppContextSetup(context)
+        .addFilters(new XSSFilter())
 				.build();
 	}
 

engine/src/test/java/io/seldon/engine/api/rest/TestRestClientController.java

@@ -18,16 +18,19 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import io.seldon.engine.filters.XSSFilter;
 import io.seldon.engine.pb.ProtoBufUtils;
 import io.seldon.engine.tracing.TracingProvider;
 import io.seldon.protos.PredictionProtos.SeldonMessage;
 import io.opentracing.mock.MockTracer;
 import io.opentracing.mock.MockSpan;
-import java.util.*;
+import javax.servlet.http.HttpServletResponse;
 import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
+import java.util.*;
+
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
 import org.springframework.boot.test.context.SpringBootTest;
@@ -43,11 +46,12 @@
 import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.util.MultiValueMap;
 import org.springframework.web.context.WebApplicationContext;
+
 import static org.mockito.Mockito.when;
 
 @RunWith(SpringRunner.class)
 @SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)
-//@AutoConfigureMockMvc
+// @AutoConfigureMockMvc
 public class TestRestClientController {
 	private final static Logger logger = LoggerFactory.getLogger(TestRestClientController.class);
 
@@ -69,6 +73,7 @@ public void setup() {
     when(mockTracingProvider.isActive()).thenReturn(true);
 		mvc = MockMvcBuilders
 				.webAppContextSetup(context)
+        .addFilters(new XSSFilter())
 				.build();
 	}
 
@@ -84,6 +89,17 @@ public void testPing() throws Exception
     	Assert.assertEquals("pong", response);
     	Assert.assertEquals(200, res.getResponse().getStatus());
     }
+
+    @Test
+    public void testSecurityHeaders() throws Exception
+    {
+    	MvcResult res = mvc.perform(MockMvcRequestBuilders.get("/ping")).andReturn();
+    	HttpServletResponse response = res.getResponse();
+
+      final String noSniff = response.getHeader("X-Content-Type-Options");
+    	Assert.assertEquals("nosniff", noSniff);
+    	Assert.assertEquals(200, response.getStatus());
+    }
 
     @Test
     public void testPredict_activateSpan() throws Exception

engine/src/test/java/io/seldon/engine/api/rest/TestRestClientControllerExternalGraphs.java

@@ -32,6 +32,7 @@
 import org.springframework.util.MultiValueMap;
 import org.springframework.web.context.WebApplicationContext;
 
+import io.seldon.engine.filters.XSSFilter;
 import io.seldon.engine.pb.JsonFormat;
 import io.seldon.engine.predictors.EnginePredictor;
 import io.seldon.engine.service.InternalPredictionService;
@@ -67,6 +68,7 @@ public void setup() throws Exception {
 
     	mvc = MockMvcBuilders
 				.webAppContextSetup(context)
+        .addFilters(new XSSFilter())
 				.build();
 	}
 

engine/src/test/java/io/seldon/engine/filters/TestXSSFilter.java

@@ -0,0 +1,29 @@
+package io.seldon.engine.filters;
+
+import java.io.IOException;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import javax.servlet.FilterChain;
+
+public class TestXSSFilter {
+  @Test
+  public void testSecurityHeaders() throws ServletException, IOException {
+    HttpServletRequest request = mock(HttpServletRequest.class);
+    HttpServletResponse response = mock(HttpServletResponse.class);
+    FilterChain chain = mock(FilterChain.class);
+
+    XSSFilter filter = new XSSFilter();
+    filter.doFilter(request, response, chain);
+
+    verify(response).addHeader("X-Content-Type-Options", "nosniff");
+    verify(chain).doFilter(request, response);
+  }
+}

engine/src/test/java/io/seldon/engine/pb/TestJsonFormat.java

@@ -0,0 +1,81 @@
+/*******************************************************************************
+ * Copyright 2019 Seldon Technologies Ltd (http://www.seldon.io/)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *         http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *******************************************************************************/
+package io.seldon.engine.pb;
+
+import com.google.protobuf.InvalidProtocolBufferException;
+
+import io.kubernetes.client.proto.IntStr.IntOrString;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import io.seldon.engine.pb.JsonFormat.Printer;
+
+public class TestJsonFormat {
+	private final static Logger logger = LoggerFactory.getLogger(TestJsonFormat.class);
+
+	@Test
+	public void testStrValCustomFormat() throws InvalidProtocolBufferException
+	{
+		final String val = "String Value";
+		IntOrString is = IntOrString.newBuilder().setStrVal(val).build();
+		Printer jf = JsonFormat.printer().usingTypeConverter(is.getDescriptorForType().getFullName(), new IntOrStringUtils.IntOrStringConverter());
+		Assert.assertEquals("\""+val+"\"", jf.print(is));
+	}
+
+  @Test
+  public void testEscapeHTML()  throws InvalidProtocolBufferException
+  {
+    final String val = "<div class=\"div-class\"></div>";
+    final String escaped = "\\u003cdiv class\\u003d\\\"div-class\\\"\\u003e\\u003c/div\\u003e";
+    final String expected = String.format("{\"strVal\":\"%s\"}", escaped);
+		IntOrString is = IntOrString.newBuilder().setStrVal(val).build();
+    Printer jf = JsonFormat.printer().omittingInsignificantWhitespace();
+    final String json = jf.print(is);
+    Assert.assertEquals(expected, json);
+  }
+
+	@Test
+	public void testIntValCustomFormat() throws InvalidProtocolBufferException
+	{
+		final int val = 1;
+		IntOrString is = IntOrString.newBuilder().setIntVal(val).build();
+		Printer jf = JsonFormat.printer().usingTypeConverter(is.getDescriptorForType().getFullName(), new IntOrStringUtils.IntOrStringConverter());
+		Assert.assertEquals(""+val, jf.print(is));
+	}
+
+	@Test
+	public void testIntValDefaultFormat() throws InvalidProtocolBufferException
+	{
+		final int val = 1;
+		IntOrString is = IntOrString.newBuilder().setIntVal(val).build();
+		Printer jf = JsonFormat.printer().omittingInsignificantWhitespace();
+		Assert.assertEquals("{\"intVal\":"+val+"}", jf.print(is));
+	}
+
+	@Test
+	public void testStrValDefaultFormat() throws InvalidProtocolBufferException
+	{
+		final String val = "String Value";
+		IntOrString is = IntOrString.newBuilder().setStrVal(val).build();
+		Printer jf = JsonFormat.printer().omittingInsignificantWhitespace();
+		Assert.assertEquals("{\"strVal\":\""+val+"\"}", jf.print(is));
+	}
+}
+

examples/models/xss/.s2i/environment

@@ -0,0 +1,4 @@
+MODEL_NAME=XSSModel
+API_TYPE=REST
+SERVICE_TYPE=MODEL
+PERSISTENCE=0

examples/models/xss/Makefile

@@ -0,0 +1,6 @@
+IMAGE_NAME=xss-model
+IMAGE_VERSION=0.1
+
+build_image:
+	s2i build . seldonio/seldon-core-s2i-python3:0.7 ${IMAGE_NAME}:${IMAGE_VERSION}
+

examples/models/xss/XSSModel.py

@@ -0,0 +1,7 @@
+class XSSModel(object):
+    """
+    Dummy model which just returns its input back.
+    """
+
+    def predict(self, X, feature_names):
+        return X