From c28cecc8670f6c3833e562afd9bf9676d1ab8b38 Mon Sep 17 00:00:00 2001 From: Jonathan Leitschuh Date: Mon, 3 Oct 2022 21:27:23 +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 Signed-off-by: Jonathan Leitschuh Bug-tracker: https://github.com/JLLeitschuh/security-research/issues/16 Co-authored-by: Moderne --- .../pippo-controller/src/test/java/ro/pippo/DynamicJar.java | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/pippo-controller-parent/pippo-controller/src/test/java/ro/pippo/DynamicJar.java b/pippo-controller-parent/pippo-controller/src/test/java/ro/pippo/DynamicJar.java index 93415b6d..c8b4577f 100644 --- a/pippo-controller-parent/pippo-controller/src/test/java/ro/pippo/DynamicJar.java +++ b/pippo-controller-parent/pippo-controller/src/test/java/ro/pippo/DynamicJar.java @@ -233,7 +233,11 @@ private void extract(Path jarPath, Path destDir) throws IOException { Enumeration enumEntries = jar.entries(); while (enumEntries.hasMoreElements()) { JarEntry entry = enumEntries.nextElement(); - File f = destDir.resolve(entry.getName()).toFile(); + final Path zipEntryPath = destDir.resolve(entry.getName()); + if (!zipEntryPath.normalize().startsWith(destDir.normalize())) { + throw new IOException("Bad zip entry"); + } + File f = zipEntryPath.toFile(); f.getParentFile().mkdirs(); InputStream is = jar.getInputStream(entry); FileOutputStream fos = new FileOutputStream(f);