vuln-fix: Temporary File Information Disclosure

This fixes temporary file information disclosure vulnerability due to the use
of the vulnerable `File.createTempFile()` method. The vulnerability is fixed by
using the `Files.createTempFile()` method which sets the correct posix permissions.

Weakness: CWE-377: Insecure Temporary File
Severity: Medium
CVSSS: 5.5
Detection: CodeQL & OpenRewrite (https://public.moderne.io/recipes/org.openrewrite.java.security.SecureTempFileCreation)

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

Bug-tracker: JLLeitschuh/security-research#18


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

src/main/java/org/jenkinsci/plugins/graniteclient/ContentSignatureCalculator.java

@@ -50,6 +50,7 @@
 import java.nio.ByteBuffer;
 import java.nio.channels.FileChannel;
 import java.nio.file.FileSystems;
+import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.StandardOpenOption;
 import java.security.MessageDigest;
@@ -132,7 +133,7 @@ private static void calculateFromEntityWriter(Request.EntityWriter entityWriter,
         File tempFile = null;
         OutputStream os = null;
         try {
-            tempFile = File.createTempFile("crxPartBase", ".dat");
+            tempFile = Files.createTempFile("crxPartBase", ".dat").toFile();
             os = new BufferedOutputStream(new FileOutputStream(tempFile));
 
             entityWriter.writeEntity(os);
@@ -154,7 +155,7 @@ private static void calculateFromPartBase(PartBase part, RequestBuilderBase<?> r
             File tempFile = null;
             OutputStream os = null;
             try {
-                tempFile = File.createTempFile("crxPartBase", ".dat");
+                tempFile = Files.createTempFile("crxPartBase", ".dat").toFile();
                 os = new BufferedOutputStream(new FileOutputStream(tempFile));
 
                 part.send(os);