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Fix zipslip for jar #448

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Fix zipslip for jar #448

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880306e
Fix zipslip for jar
idawson-gl Dec 17, 2024
f83a3f0
Fix zipslip in DirectoryResultSaver
idawson-gl Dec 17, 2024
4b5981d
Remove test jar
idawson-gl Dec 17, 2024
772455f
Remove unnecessary imports
idawson-gl Dec 17, 2024
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11 changes: 10 additions & 1 deletion src/org/jetbrains/java/decompiler/main/decompiler/DirectoryResultSaver.java
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Original file line number Diff line number Diff line change
Expand Up @@ -5,6 +5,7 @@
import org.jetbrains.java.decompiler.util.InterpreterUtil;

import java.io.*;
import java.nio.file.FileSystems;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.jar.Manifest;
Expand Down Expand Up @@ -82,11 +83,19 @@ public void saveClassFile(String path, String qualifiedName, String entryName, S

@Override
public void copyEntry(String source, String path, String archiveName, String entryName) {
String rootPath = this.root.toString();

try (ZipFile srcArchive = new ZipFile(new File(source))) {
ZipEntry entry = srcArchive.getEntry(entryName);
if (entry != null) {
try (InputStream in = srcArchive.getInputStream(entry)) {
InterpreterUtil.copyStream(in, new FileOutputStream(this.root.resolve(entryName).toFile()));
String cleanedPath = FileSystems.getDefault().getPath("/"+entryName).normalize().toString();
File joinedPath = java.nio.file.Paths.get(rootPath, cleanedPath).toFile();
if (!joinedPath.toString().startsWith(rootPath)) {
throw new IOException("unable to verify safe file path");
}

InterpreterUtil.copyStream(in, new FileOutputStream(joinedPath));
}
}
}
Expand Down
29 changes: 29 additions & 0 deletions test/org/jetbrains/java/decompiler/CommandLineTest.java
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Original file line number Diff line number Diff line change
Expand Up @@ -6,9 +6,14 @@
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;

import static org.jetbrains.java.decompiler.DecompilerTestFixture.assertFilesEqual;
import static org.junit.jupiter.api.Assertions.assertFalse;

public class CommandLineTest {
private DecompilerTestFixture fixture;
Expand Down Expand Up @@ -48,6 +53,30 @@ public void testJarToDir() {
assertFilesEqual(fixture.getTestDataDir().resolve("bulk"), fixture.getTempDir().resolve("bulk_out"));
}

@Test
public void testMaliciousJarToDir() throws IOException {
String out = fixture.getTempDir().resolve("bulk_out").toAbsolutePath().toString();
String in = fixture.getTestDataDir().resolve("mal.jar").toAbsolutePath().toString();
// create malicious jar if doesn't exist already
if (!new File(in).exists())
{
String badFileName = new String("../../../../../../../../../../../tmp/test.txt");
try (ZipOutputStream maliciousOut = new ZipOutputStream(new FileOutputStream(fixture.getTestDataDir().resolve("mal.jar").toAbsolutePath().toString())))
{
ZipEntry entry = new ZipEntry(badFileName);
maliciousOut.putNextEntry(entry);
maliciousOut.write("womp womp".getBytes());
maliciousOut.closeEntry();
}
}

ConsoleDecompiler.main(new String[]{in, out});

TextBuffer.checkLeaks();
File f = new File("/tmp/test.txt");
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@wagyourtail wagyourtail Mar 8, 2025 •
edited
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I would suggest using a more distinct file name... I could just have a /tmp/test.txt already on my system. also should probably have a windows version of the test too.

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JUnit also has a way to generate a test-specific temp file directory, that's probably the way to go

assertFalse(f.exists());
}

@Test
public void testZipToJar() {
String out = fixture.getTempDir().resolve("bulk_out.jar").toAbsolutePath().toString();
Expand Down