An authenticated local file inclusion vulnerability exists in Microweber CMS versions <= 1.2.11 through misuse of the backup management API. Authenticated users can abuse the /api/BackupV2/upload and /api/BackupV2/download endpoints to read arbitrary files from the underlying filesystem. By specifying an absolute file path in the src parameter of the upload request, the server may relocate or delete the target file depending on the web service user’s privileges. The corresponding download endpoint can then be used to retrieve the file contents, effectively enabling local file disclosure. This behavior stems from insufficient validation of user-supplied paths and inadequate restrictions on file access and backup logic.
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.