Evil-WinRM - Path Traversal in download_dir() Function

Summary

Evil-WinRM through 3.9, fixed in commit 6ecd570, contains a path traversal vulnerability in the download_dir() function that allows a rogue or compromised remote Windows server to write files outside the intended download directory by returning filenames with traversal sequences from Get-ChildItem command output that are passed unsanitized to File.join(). Attackers controlling the remote server can exploit this to overwrite sensitive client-side files such as SSH authorized_keys or shell configuration files, achieving persistent access or privilege escalation on the client machine.