From 0c9f1e9d69a08ed35648eb85dae01d2592b72403 Mon Sep 17 00:00:00 2001
From: Odinn <odinn@Odinns-MacBook-Pro.local>
Date: Sun, 6 May 2018 01:16:55 +0300
Subject: [PATCH 2/2] fix: fail when trying to extract outside of dest dir

A well crafted zip file may cause the code to extract outside of the destination dir.
This PR fails when that happens so that no unexpected behaviour happens.
---
 .../plexus/archiver/AbstractUnArchiver.java        |   9 ++++++++
 .../plexus/archiver/zip/ZipUnArchiverTest.java     |  24 +++++++++++++++++++++
 src/test/zips/zip-slip.zip                         | Bin 0 -> 545 bytes
 3 files changed, 33 insertions(+)
 create mode 100644 src/test/zips/zip-slip.zip

diff --git a/src/main/java/org/codehaus/plexus/archiver/AbstractUnArchiver.java b/src/main/java/org/codehaus/plexus/archiver/AbstractUnArchiver.java
index bd462d9..9675880 100644
--- a/src/main/java/org/codehaus/plexus/archiver/AbstractUnArchiver.java
+++ b/src/main/java/org/codehaus/plexus/archiver/AbstractUnArchiver.java
@@ -308,6 +308,15 @@ protected void extractFile( final File srcF, final File dir, final InputStream c
         // Hmm. Symlinks re-evaluate back to the original file here. Unsure if this is a good thing...
         final File f = FileUtils.resolveFile( dir, entryName );
 
+        // Make sure that the resolved path of the extracted file doesn't escape the destination directory
+        String canonicalDirPath = dir.getCanonicalPath();
+        String canonicalDestPath = f.getCanonicalPath();
+
+        if ( !canonicalDestPath.startsWith( canonicalDirPath ) )
+        {
+            throw new ArchiverException( "Entry is outside of the target directory (" + entryName + ")" );
+        }
+
         try
         {
             if ( !isOverwrite() && f.exists() && ( f.lastModified() >= entryDate.getTime() ) )
diff --git a/src/test/java/org/codehaus/plexus/archiver/zip/ZipUnArchiverTest.java b/src/test/java/org/codehaus/plexus/archiver/zip/ZipUnArchiverTest.java
index 1f72a61..ea46a5a 100644
--- a/src/test/java/org/codehaus/plexus/archiver/zip/ZipUnArchiverTest.java
+++ b/src/test/java/org/codehaus/plexus/archiver/zip/ZipUnArchiverTest.java
@@ -190,6 +190,30 @@ public void testSelectors()
                        } );
     }
 
+    public void testExtractingZipWithEntryOutsideDestDirThrowsException()
+            throws Exception
+    {
+        Exception ex = null;
+        String s = "target/zip-unarchiver-slip-tests";
+        File testZip = new File( getBasedir(), "src/test/zips/zip-slip.zip" );
+        File outputDirectory = new File( getBasedir(), s );
+
+        FileUtils.deleteDirectory( outputDirectory );
+
+        try
+        {
+            ZipUnArchiver zu = getZipUnArchiver( testZip );
+            zu.extract( "", outputDirectory );
+        }
+        catch ( Exception e )
+        {
+            ex = e;
+        }
+
+        assertNotNull( ex );
+        assertTrue( ex.getMessage().startsWith( "Entry is outside of the target directory" ) );
+    }
+
     private ZipArchiver getZipArchiver()
     {
         try
diff --git a/src/test/zips/zip-slip.zip b/src/test/zips/zip-slip.zip
new file mode 100644
index 0000000..38b3f49
--- /dev/null
+++ b/src/test/zips/zip-slip.zip
@@ -0,0 +1,5 @@
+PK
+