From e93abe18bea75a40e440f528467ae7009c29e479 Mon Sep 17 00:00:00 2001 From: Jonathan Leitschuh Date: Fri, 29 Jul 2022 13:24:54 +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/cloudsync/connector/LocalFilesystemConnector.java | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) mode change 100755 => 100644 src/main/java/cloudsync/connector/LocalFilesystemConnector.java diff --git a/src/main/java/cloudsync/connector/LocalFilesystemConnector.java b/src/main/java/cloudsync/connector/LocalFilesystemConnector.java old mode 100755 new mode 100644 index b633b86..48df626 --- a/src/main/java/cloudsync/connector/LocalFilesystemConnector.java +++ b/src/main/java/cloudsync/connector/LocalFilesystemConnector.java @@ -510,7 +510,7 @@ public Item getItem(File file, final FollowLinkType followlinks, List fo } target = Paths.get(target).toFile().getCanonicalPath(); - if (!followlinks.equals(FollowLinkType.NONE) && followlinks.equals(FollowLinkType.EXTERNAL) && !target.startsWith(localPath + Item.SEPARATOR) ) + if (!followlinks.equals(FollowLinkType.NONE) && followlinks.equals(FollowLinkType.EXTERNAL) && !Paths.get(target).toFile().getCanonicalFile().toPath().startsWith(localPath + Item.SEPARATOR) ) { boolean foundLink = false; for( String followedLinkPath: followedLinkPaths )