From 950266f6de7aa062b7dd3dbe5c21659572f2ed17 Mon Sep 17 00:00:00 2001
From: Jonathan Leitschuh <Jonathan.Leitschuh@gmail.com>
Date: Fri, 23 Sep 2022 03:45:28 +0000
Subject: [PATCH] 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 <Jonathan.Leitschuh@gmail.com>
Signed-off-by: Jonathan Leitschuh <Jonathan.Leitschuh@gmail.com>

Bug-tracker: https://github.com/JLLeitschuh/security-research/issues/16

Co-authored-by: Moderne <team@moderne.io>
---
 .../org/jaggeryjs/hostobjects/file/FileHostObject.java    | 5 ++---
 .../jaggeryjs/jaggery/app/mgt/JaggeryDeploymentUtil.java  | 8 ++++++--
 2 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/components/hostobjects/org.jaggeryjs.hostobjects.file/src/main/java/org/jaggeryjs/hostobjects/file/FileHostObject.java b/components/hostobjects/org.jaggeryjs.hostobjects.file/src/main/java/org/jaggeryjs/hostobjects/file/FileHostObject.java
index e32eba43..5603ef15 100644
--- a/components/hostobjects/org.jaggeryjs.hostobjects.file/src/main/java/org/jaggeryjs/hostobjects/file/FileHostObject.java
+++ b/components/hostobjects/org.jaggeryjs.hostobjects.file/src/main/java/org/jaggeryjs/hostobjects/file/FileHostObject.java
@@ -411,8 +411,7 @@ public static boolean jsFunction_unZip(Context cx, Scriptable thisObj, Object[]
                         while ((entry = zin.getNextEntry()) != null) {
                             name = entry.getName();
                             String canonicalDirPath = outdir.getCanonicalPath();
-                            String canonicalEntryPath = new File(canonicalDirPath + entry.getName()).getCanonicalPath();
-                            if(!canonicalEntryPath.startsWith(canonicalDirPath)){
+                            if(!new File(canonicalDirPath + entry.getName()).getCanonicalFile().toPath().startsWith(canonicalDirPath)){
                                 log.error("Invalid entry found in the Zip file: " + name);
                                 return false;
                             }
@@ -605,4 +604,4 @@ private static boolean mkdirs(File parentDirectory, String path) {
         File dir = new File(parentDirectory, path);
         return dir.exists() || dir.mkdirs();
     }
-}
\ No newline at end of file
+}
diff --git a/components/jaggery-core/org.jaggeryjs.jaggery.app.mgt/src/main/java/org/jaggeryjs/jaggery/app/mgt/JaggeryDeploymentUtil.java b/components/jaggery-core/org.jaggeryjs.jaggery.app.mgt/src/main/java/org/jaggeryjs/jaggery/app/mgt/JaggeryDeploymentUtil.java
index ef739a09..00120517 100644
--- a/components/jaggery-core/org.jaggeryjs.jaggery.app.mgt/src/main/java/org/jaggeryjs/jaggery/app/mgt/JaggeryDeploymentUtil.java
+++ b/components/jaggery-core/org.jaggeryjs.jaggery.app.mgt/src/main/java/org/jaggeryjs/jaggery/app/mgt/JaggeryDeploymentUtil.java
@@ -44,7 +44,7 @@ static void unZip(InputStream is, String destDir) {
             ZipEntry entry;
             while ((entry = zis.getNextEntry()) != null) {
                 if (entry.isDirectory()) {
-                    File entryDir = new File(unzipDestinationDirectory.getAbsolutePath() + File.separator + entry.getName());
+                    File entryDir = new File(unzipDestinationDirectory.getAbsolutePath(), entry.getName());
                     boolean created = entryDir.mkdir();
                     if (!created) {
                     	log.error("Could not create DIR : " + unzipDestinationDirectory.getAbsolutePath() + 
@@ -56,7 +56,11 @@ static void unZip(InputStream is, String destDir) {
                     // write the files to the disk
                     FileOutputStream fos = null;
                     try {
-	                    fos = new FileOutputStream(unzipDestinationDirectory.getAbsolutePath() + File.separator + entry.getName());
+                        final File zipEntryFile = new File(unzipDestinationDirectory.getAbsolutePath(), entry.getName());
+                        if (!zipEntryFile.toPath().normalize().startsWith(unzipDestinationDirectory.getAbsolutePath())) {
+                            throw new IOException("Bad zip entry");
+                        }
+                        fos = new FileOutputStream(zipEntryFile);
 	                    dest = new BufferedOutputStream(fos, BYTE_BUFFER_SIZE);
 	                    while ((count = zis.read(data, 0, BYTE_BUFFER_SIZE))
 	                            != -1) {