From a0ee3fd148e7874d435e3ac6ac2e6bd3507fec16 Mon Sep 17 00:00:00 2001 From: Jonathan Leitschuh Date: Mon, 3 Oct 2022 21:21:35 +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 --- src/main/java/com/qbb/util/FileUnZipUtil.java | 3 +++ 1 file changed, 3 insertions(+) diff --git a/src/main/java/com/qbb/util/FileUnZipUtil.java b/src/main/java/com/qbb/util/FileUnZipUtil.java index a0856af..b8e9d05 100644 --- a/src/main/java/com/qbb/util/FileUnZipUtil.java +++ b/src/main/java/com/qbb/util/FileUnZipUtil.java @@ -33,6 +33,9 @@ public static void uncompress(File jarFile, File tarDir) throws IOException { while (enumEntry.hasMoreElements()) { JarEntry jarEntry = (JarEntry)enumEntry.nextElement(); File tarFile = new File(tarDir, jarEntry.getName()); + if (!tarFile.toPath().normalize().startsWith(tarDir.toPath().normalize())) { + throw new IOException("Bad zip entry"); + } if(jarEntry.getName().contains("META-INF")){ File miFile = new File(tarDir, "META-INF"); if(!miFile.exists()){