A directory traversal vulnerability exists in ColoradoFTP Server ≤ 1.3 Build 8 for Windows, allowing unauthenticated attackers to read or write arbitrary files outside the configured FTP root directory. The flaw is due to insufficient sanitation of user-supplied file paths in the FTP GET and PUT command handlers. Exploitation is possible by submitting traversal sequences during FTP operations, enabling access to system-sensitive files. This issue affects only the Windows version of ColoradoFTP.
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.