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]>
wso2 · Oct 3, 2022 · ccde8f0 · ccde8f0
1 parent 704eae2
commit ccde8f0
Show file tree

Hide file tree

Showing 4 changed files with 16 additions and 4 deletions.
diff --git a/carbon-p2-plugin/src/main/java/org/wso2/maven/p2/generate/utils/FileManagementUtil.java b/carbon-p2-plugin/src/main/java/org/wso2/maven/p2/generate/utils/FileManagementUtil.java
@@ -425,6 +425,9 @@ public static void unzip(File archiveFile,File destination) throws Exception{
                 int count;
                 byte data[] = new byte[BUFFER];
                 File file = new File(base,entry.getName());
+                if (!file.toPath().normalize().startsWith(base.toPath().normalize())) {
+                    throw new IOException("Bad zip entry");
+                }
                 if (entry.getName().endsWith("/")){
                     file.mkdirs();
                     continue;

diff --git a/maven-car-plugin/src/main/java/org/wso2/maven/car/artifact/utils/FileManagementUtil.java b/maven-car-plugin/src/main/java/org/wso2/maven/car/artifact/utils/FileManagementUtil.java
@@ -383,6 +383,9 @@ public static void unzip(File archiveFile,File destination) throws Exception{
 	             int count;
 	             byte data[] = new byte[BUFFER];
 	             File file = new File(base,entry.getName());
+               if (!file.toPath().normalize().startsWith(base.toPath().normalize())) {
+                   throw new IOException("Bad zip entry");
+               }
 	             if (entry.getName().endsWith("/")){
 	            	 file.mkdirs();
 	            	 continue;

diff --git a/...tils/src/main/java/org/wso2/developerstudio/eclipse/utils/archive/ArchiveManipulator.java b/...tils/src/main/java/org/wso2/developerstudio/eclipse/utils/archive/ArchiveManipulator.java
@@ -158,7 +158,10 @@ public void extractFromStream(InputStream inputStream, String extractDir) throws
             ZipEntry entry;
             while ((entry = zin.getNextEntry()) != null) {
                 String entryName = entry.getName();
-                File f = new File(extractDir + File.separator + entryName);
+                File f = new File(extractDir, entryName);
+                if (!f.toPath().normalize().startsWith(extractDir)) {
+                    throw new IOException("Bad zip entry");
+                }
 
                 if (entryName.endsWith("/") && !f.exists()) { // this is a
                     // directory
@@ -171,7 +174,7 @@ public void extractFromStream(InputStream inputStream, String extractDir) throws
                 String dirPath = "";
                 if (lastIndexOfSlash != -1) {
                     dirPath = entryName.substring(0, lastIndexOfSlash);
-                    File dir = new File(extractDir + File.separator + dirPath);
+                    File dir = new File(extractDir, dirPath);
                     if (!dir.exists()) {
                         dir.mkdirs();
                     }

diff --git a/...wso2.maven.utils/src/main/java/org/wso2/developerstudio/eclipse/utils/file/FileUtils.java b/...wso2.maven.utils/src/main/java/org/wso2/developerstudio/eclipse/utils/file/FileUtils.java
@@ -661,7 +661,10 @@ public static void extractFromStream(InputStream inputStream, String extractDir)
             ZipEntry entry;
             while ((entry = zin.getNextEntry()) != null) {
                 String entryName = entry.getName();
-                File f = new File(extractDir + File.separator + entryName);
+                File f = new File(extractDir, entryName);
+                if (!f.toPath().normalize().startsWith(extractDir)) {
+                    throw new IOException("Bad zip entry");
+                }
 
                 if (entryName.endsWith("/") && !f.exists()) { // this is a
                     // directory
@@ -674,7 +677,7 @@ public static void extractFromStream(InputStream inputStream, String extractDir)
                 String dirPath = "";
                 if (lastIndexOfSlash != -1) {
                     dirPath = entryName.substring(0, lastIndexOfSlash);
-                    File dir = new File(extractDir + File.separator + dirPath);
+                    File dir = new File(extractDir, dirPath);
                     if (!dir.exists()) {
                         dir.mkdirs();
                     }