CVE-2022-41720

Summary

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.

Affected Software

VendorProductVersion RangeStatus
Go standard libraryos0 < 1.18.9affected
Go standard libraryos1.19.0-0 < 1.19.4affected
Go standard librarynet/http0 < 1.18.9affected
Go standard librarynet/http1.19.0-0 < 1.19.4affected

Weaknesses

  • CWE 22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

ADP Enrichment

CVE Program Container

Additional References

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: yes
    • Technical Impact: partial

References