CVE-2022-41720

Published: 7 December 2022

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.

Notes

Packages built using golang need to be rebuilt once the
vulnerability has been fixed. This CVE entry does not
list packages that need rebuilding outside of the main
repository or the Ubuntu variants with PPA overlays.

Only affects golang on Windows

Status

Severity score breakdown

References

• https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-41720
• https://groups.google.com/g/golang-announce/c/L_3rmdT0BMU/m/yZDrXjIiBQAJ
• https://pkg.go.dev/vuln/GO-2022-1143
• https://go.dev/cl/455716
• https://go.dev/issue/56694
• NVD
• Launchpad
• Debian