The filepath package does not recognize paths with a \??\ prefix as special. On Windows, a path beginning with \??\ is a Root Local Device path equivalent to a path beginning with \\?\. Paths with a \??\ prefix may be used to access arbitrary locations on the system. For example, the path \??\c:\x is equivalent to the more common path c:\x. Before fix, Clean could convert a rooted path such as \a\..\??\b into the root local device path \??\b. Clean will now convert this to .\??\b. Similarly, Join(\, ??, b) could convert a seemingly innocent sequence of path elements into the root local device path \??\b. Join will now convert this to \.\??\b. In addition, with fix, IsAbs now correctly reports paths beginning with \??\ as absolute, and VolumeName correctly reports the \??\ prefix as a volume name. UPDATE: Go 1.20.11 and Go 1.21.4 inadvertently changed the definition of the volume name in Windows paths starting with \?, resulting in filepath.Clean(\?\c:) returning \?\c: rather than \?\c:\ (among other effects). The previous behavior has been restored.
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
| Link | Tags |
|---|---|
| https://go.dev/issue/63713 | vendor advisory issue tracking |
| https://go.dev/cl/540277 | vendor advisory issue tracking |
| https://groups.google.com/g/golang-announce/c/4tU8LZfBFkY | vendor advisory mailing list issue tracking |
| https://go.dev/issue/64028 | |
| https://go.dev/cl/541175 | |
| https://groups.google.com/g/golang-dev/c/6ypN5EjibjM/m/KmLVYH_uAgAJ | |
| https://pkg.go.dev/vuln/GO-2023-2185 | vendor advisory issue tracking |
| http://www.openwall.com/lists/oss-security/2023/12/05/2 | |
| https://security.netapp.com/advisory/ntap-20231214-0008/ |