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.
https://www.vulncheck.com/advisories/evil-winrm-path-traversal-in-download-dir-function
https://github.com/Hackplayers/evil-winrm/pull/81
https://github.com/Hackplayers/evil-winrm/commit/6ecd570a298562dc72ad73978307eb34182f5850
Published: 2026-06-17
Base Score: 7.1
Vector: CVSS2#AV:N/AC:H/Au:N/C:C/I:C/A:N
Severity: High
Base Score: 6.8
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
Severity: Medium
Base Score: 7.4
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
Severity: High