vuln-fix: Zip Slip Vulnerability

This fixes a Zip-Slip vulnerability.

This change does one of two things. This change either

1. Inserts a guard to protect against Zip Slip.
OR
2. Replaces `dir.getCanonicalPath().startsWith(parent.getCanonicalPath())`, which is vulnerable to partial path traversal attacks, with the more secure `dir.getCanonicalFile().toPath().startsWith(parent.getCanonicalFile().toPath())`.

For number 2, consider `"/usr/outnot".startsWith("/usr/out")`.
The check is bypassed although `/outnot` is not under the `/out` directory.
It's important to understand that the terminating slash may be removed when using various `String` representations of the `File` object.
For example, on Linux, `println(new File("/var"))` will print `/var`, but `println(new File("/var", "/")` will print `/var/`;
however, `println(new File("/var", "/").getCanonicalPath())` will print `/var`.

Weakness: CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Severity: High
CVSSS: 7.4
Detection: CodeQL (https://codeql.github.com/codeql-query-help/java/java-zipslip/) & OpenRewrite (https://public.moderne.io/recipes/org.openrewrite.java.security.ZipSlip)

Reported-by: Jonathan Leitschuh <[email protected]>
Signed-off-by: Jonathan Leitschuh <[email protected]>

Bug-tracker: JLLeitschuh/security-research#16


Co-authored-by: Moderne <[email protected]>

dependency-check-core/src/main/java/org/owasp/dependencycheck/utils/ExtractionUtil.java

@@ -107,6 +107,9 @@ public static void extractFiles(File archive, File extractTo, Engine engine) thr
                     }
                 } else {
                     final File file = new File(extractTo, entry.getName());
+                    if (!file.toPath().normalize().startsWith(extractTo.toPath().normalize())) {
+                        throw new RuntimeException("Bad zip entry");
+                    }
                     if (engine == null || engine.accept(file)) {
                         BufferedOutputStream bos = null;
                         FileOutputStream fos;

dependency-check-core/src/test/java/org/owasp/dependencycheck/data/nvdcve/BaseDBTestCase.java

@@ -17,11 +17,7 @@
  */
 package org.owasp.dependencycheck.data.nvdcve;
 
-import java.io.BufferedInputStream;
-import java.io.BufferedOutputStream;
-import java.io.File;
-import java.io.FileInputStream;
-import java.io.FileOutputStream;
+import java.io.*;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipInputStream;
 import org.junit.Before;
@@ -72,6 +68,9 @@ public static void ensureDBExists() throws Exception {
                     BufferedOutputStream dest = null;
                     try {
                         File o = new File(dataPath, entry.getName());
+                        if (!o.toPath().normalize().startsWith(dataPath.toPath().normalize())) {
+                            throw new IOException("Bad zip entry");
+                        }
                         o.createNewFile();
                         fos = new FileOutputStream(o, false);
                         dest = new BufferedOutputStream(fos, BUFFER_SIZE);