Laravel Excel provides supercharged Excel exports and imports in Laravel. From 3.1.8 until 3.1.70, in src/Files/Disk.php the Maatwebsite\Excel\Files\Disk::copy() method resolves the caller-controlled $destination supplied through Excel::store(), $export->store(), or storeExcel() against the process working directory with realpath() instead of the configured filesystem disk. If the path names an existing writable file, Disk::copy() opens it with fopen() in rb+ mode and uses stream_copy_to_stream(), bypassing Flysystem path confinement and allowing an attacker whose application input controls the export path to overwrite arbitrary existing files with export content.
The rb+ behavior creates a non-truncating overwrite and trailing bytes when the new export is shorter, and overwriting an executable PHP file can lead to remote code execution. This issue is fixed in version 3.1.70.
Attack Parameters
Impact Assessment
CVSS Vector v3.1