CVE-2022-41720

On Windows, restricted files can be accessed via os.DirFS and http.Dir. The os.DirFS function and http.Dir type provide access to a tree of files rooted at a given directory. These functions permit access to Windows device files under that root. For example, os.DirFS("C:/tmp").Open("COM1") opens the COM1 device. Both os.DirFS and http.Dir only provide read-only filesystem access. In addition, on Windows, an os.DirFS for the directory (the root of the current drive) can permit a maliciously crafted path to escape from the drive and access any path on the system. With fix applied, the behavior of os.DirFS("") has changed. Previously, an empty root was treated equivalently to "/", so os.DirFS("").Open("tmp") would open the path "/tmp". This now returns an error.

• CWE-22

• https://go.dev/cl/455716Patch, Vendor Advisory
• https://go.dev/issue/56694Issue Tracking, Vendor Advisory
• https://groups.google.com/g/golang-announce/c/L_3rmdT0BMU/m/yZDrXjIiBQAJPatch, Release Notes, Third Party Advisory
• https://pkg.go.dev/vuln/GO-2022-1143Patch, Vendor Advisory
• https://go.dev/cl/455716Patch, Vendor Advisory
• https://go.dev/issue/56694Issue Tracking, Vendor Advisory
• https://groups.google.com/g/golang-announce/c/L_3rmdT0BMU/m/yZDrXjIiBQAJPatch, Release Notes, Third Party Advisory
• https://pkg.go.dev/vuln/GO-2022-1143Patch, Vendor Advisory

Published

Dec 7, 2022

Last Modified

Jun 17, 2026

Status

Modified