S40 CMS v0.4.2 contains a path traversal vulnerability in its index.php page handler. The p parameter is not properly sanitized, allowing attackers to traverse the file system and access arbitrary files outside the web root. This can be exploited remotely without authentication by appending traversal sequences and a null byte to bypass file extension checks.
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.