Improper Input Validation
Unrestricted file upload vulnerability in the DownloadsPlus module in PHP-Nuke allows remote attackers to execute arbitrary code by uploading a file with (1) .htm, (2) .html, or (3) .txt extensions, then accessing it via a direct request to the file. NOTE: the provenance of this information is unknown; the details are obtained solely from third party information. NOTE: it is unclear how allowing the upload of .html or .txt files supports arbitrary code execution; this might be legitimate functionality.
CWE-20 - Improper Input Validation
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.