From 0b5847ccf426355c6b4d2f4858a4212073a30160 Mon Sep 17 00:00:00 2001 From: Jonathan Leitschuh Date: Fri, 29 Jul 2022 13:25:09 +0000 Subject: [PATCH] vuln-fix: Partial Path Traversal Vulnerability This fixes a partial path traversal vulnerability. 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())`. To demonstrate this vulnerability, 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: Medium CVSSS: 6.1 Detection: CodeQL & OpenRewrite (https://public.moderne.io/recipes/org.openrewrite.java.security.PartialPathTraversalVulnerability) Reported-by: Jonathan Leitschuh Signed-off-by: Jonathan Leitschuh Bug-tracker: https://github.com/JLLeitschuh/security-research/issues/13 Co-authored-by: Moderne --- src/main/java/io/micronaut/build/services/DockerService.java | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/src/main/java/io/micronaut/build/services/DockerService.java b/src/main/java/io/micronaut/build/services/DockerService.java index e2d6b7af4..0f3bb5f34 100644 --- a/src/main/java/io/micronaut/build/services/DockerService.java +++ b/src/main/java/io/micronaut/build/services/DockerService.java @@ -116,8 +116,7 @@ public File copyFromContainer(String imageId, String containerPath) { try (TarArchiveInputStream fin = new TarArchiveInputStream(nativeImage)) { TarArchiveEntry tarEntry = fin.getNextTarEntry(); File file = new File(mavenProject.getBuild().getDirectory(), tarEntry.getName()); - String canonicalDestinationPath = file.getCanonicalPath(); - if (!canonicalDestinationPath.startsWith(mavenProject.getBuild().getDirectory())) { + if (!file.getCanonicalFile().toPath().startsWith(mavenProject.getBuild().getDirectory())) { throw new IOException("Entry is outside of the target directory"); }