Flutter receive_sharing_intent on Android lets a rival app write files

The Android implementation of the Flutter/Dart receive_sharing_intent package, versions 1.4.1 through 1.9.0, contains a path traversal vulnerability in FileDirectory.getDataColumn that allows a malicious co-resident application to write files outside the intended cache directory by supplying a crafted _display_name value from an untrusted ContentProvider. Attackers can use a path-shaped display name ../databases/proof.txt combined with a controlled content stream to write to arbitrary locations within the receiving application's private sandbox under its UID, achieving file overwrite without user interaction.