From 51885a6bf57a9625e7486341949bfd0a26075528 Mon Sep 17 00:00:00 2001 From: Jonathan Leitschuh Date: Wed, 21 Sep 2022 15:26:01 +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 --- .../nl/b3p/viewer/stripes/ComponentResourceActionBean.java | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/viewer/src/main/java/nl/b3p/viewer/stripes/ComponentResourceActionBean.java b/viewer/src/main/java/nl/b3p/viewer/stripes/ComponentResourceActionBean.java index 7fa2193b14..310b85958f 100644 --- a/viewer/src/main/java/nl/b3p/viewer/stripes/ComponentResourceActionBean.java +++ b/viewer/src/main/java/nl/b3p/viewer/stripes/ComponentResourceActionBean.java @@ -56,8 +56,7 @@ public Resolution resource() throws IOException{ return new ErrorResolution(HttpServletResponse.SC_NOT_FOUND,"Resource not found"); } //check if the file requested is in the path of the component - String check = file.getCanonicalPath(); - if (!check.startsWith(comp.getPath())){ + if (!file.getCanonicalFile().toPath().startsWith(comp.getPath())){ return new ErrorResolution(HttpServletResponse.SC_FORBIDDEN,"Not allowed to access file"); }