Issue #513: Use IOException for invalid ZIP entries

src/main/java/org/apache/maven/buildcache/CacheUtils.java

@@ -286,7 +286,7 @@ public static void unzip(Path zip, Path out, boolean preservePermissions, boolea
                 ZipArchiveEntry entry = entries.nextElement();
                 Path file = out.resolve(entry.getName());
                 if (!file.normalize().startsWith(out.normalize())) {
-                    throw new RuntimeException("Bad zip entry");
+                    throw new IOException("Bad zip entry");
                 }
                 if (entry.isDirectory()) {
                     Files.createDirectories(file);

src/test/java/org/apache/maven/buildcache/CacheUtilsTest.java

@@ -0,0 +1,55 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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 org.apache.maven.buildcache;
+
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipOutputStream;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+class CacheUtilsTest {
+
+    @Test
+    void rejectsZipEntryOutsideOutputDirectory(@TempDir Path tempDir) throws IOException {
+        Path zip = tempDir.resolve("bad.zip");
+        Path output = tempDir.resolve("output");
+        Path outsideFile = tempDir.resolve("outside.txt");
+
+        Files.createDirectories(output);
+
+        try (ZipOutputStream zipOutput = new ZipOutputStream(Files.newOutputStream(zip))) {
+            ZipEntry entry = new ZipEntry("../outside.txt");
+            zipOutput.putNextEntry(entry);
+            zipOutput.write("test".getBytes(StandardCharsets.UTF_8));
+            zipOutput.closeEntry();
+        }
+
+        assertThrows(IOException.class, () -> CacheUtils.unzip(zip, output, false));
+
+        assertFalse(Files.exists(outsideFile));
+    }
+}