Apache Commons VFS: Possible path traversal issue when using NameScope.DESCENDENT

Relative Path Traversal vulnerability in Apache Commons VFS before 2.10.0. The FileObject API in Commons VFS has a 'resolveFile' method that takes a 'scope' parameter. Specifying 'NameScope.DESCENDENT' promises that "an exception is thrown if the resolved file is not a descendent of the base file". However, when the path contains encoded ".." characters (for example, "%2E%2E/bar.txt"), it might return file objects that are not a descendent of the base file, without throwing an exception. This issue affects Apache Commons VFS: before 2.10.0. Users are recommended to upgrade to version 2.10.0, which fixes the issue.