Calmho

**Name of the Vulnerable Software and Affected Versions** Go versions prior to 1.20.11 and 1.21.4 Go versions 1.20.11 and 1.21.4 **Description** 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 the 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 the fix, `IsAbs` now correctly reports paths beginning with `??` as absolute, and `VolumeName` correctly reports the `??` prefix as a volume name. **Recommendations** For Go versions prior to 1.20.11 and 1.21.4, update to Go 1.20.11 or 1.21.4 or later to fix the issue. For Go versions 1.20.11 and 1.21.4, update to Go 1.21.5 or later to fix the issue. As a temporary workaround, consider restricting the use of the `filepath` package until a patch is available. Restrict access to the `Clean` and `Join` functions to minimize the risk of exploitation. Avoid using the `??` prefix in paths until the issue is resolved.